Senate Republicans have mixed reactions to the surprise announcement that the Justice Department has appointed former FBI Director Robert Mueller as a special counsel to oversee a federal investigation into possible collusion between Russia and the Trump campaign in 2016.

The Justice Department on Wednesday appointed former FBI Director Robert Mueller to lead the investigation. Mueller will have sweeping powers and the authority to prosecute any crimes he uncovers.

Senate Intelligence Committee Chairman Richard Burr who considered the appointment as a good decision said that ousted National Security Adviser Michael Flynn will not honor a subpoena issued by a Senate committee looking into Russia's meddling in the 2016 presidential election. Burr told reporters Thursday that Flynn's lawyer informed the panel he will not abide by a subpoena for private documents.

President Donald Trump lashed out at the appointment of a special counsel to investigate allegations that his campaign collaborated with Russia to sway the 2016 election, tweeting Thursday that it is "the single greatest witch hunt of a politician in American history!"

Reactions from Congress to Mueller's appointment were mainly positive, even though Republicans had dismissed an independent outside investigation as unnecessary and duplicative of what congressional committees already are doing.

Sen. John McCain of Arizona, the Republican chairman of the Armed Services Committee, says it's a "scandal" of Watergate proportions, and the only way to end it is to get out the full truth.

Republicans have largely stood behind Trump in the first months of his presidency as the FBI and congressional investigations into Russia's election meddling intensified. But GOP lawmakers have grown increasingly anxious since Trump fired Comey, who had been leading the bureau's probe - and after Comey associates said he had notes from a meeting in which Trump asked him to shut down the investigation into the Russia ties of former National Security Adviser Michael Flynn.

Washington - May 18, 2017

++SEPARATED BY BLACK++

1. SOUNDBITE (English) Sen. Richard Burr, (R) North Carolina:

"General Flynn's lawyer said that he would not honor the subpoena and that's not a surprise to the committee. But we'll figure out on General Flynn what the next step, if any, is. But we're continuing on with a lot of interviews and through those interviews it leads us to additional document requests and additional individuals we'd like to talk to."

2. SOUNDBITE (English) Sen. Richard Burr, (R) North Carolina:

"Director Comey is a public citizen now. He's not constrained by investigations and we think the most important thing that Director Comey can contribute now is an understanding by the American people of what transpired. We happen to think that an open hearing in front of the intelligence committee is the right way for him to do it since we've worked so closely with him and we respect him so much."

3. SOUNDBITE (English) Sen. Lindsey Graham, (R) South Carolina:

"Clearly foreign governments could interfere in our election, they did this time. They may be more successful next time. So the shape and the scope of the congressional investigation I think has dramatically changed. I respect the decision. Mueller is a good guy. But one of the big losers here is the public because we're not going to hear from Comey now most likely. I hope we do. I want to hear about the conversation. I want to know the context of it. But now that you have a special counsel, maybe that's off the table."

4. SOUNDBITE (English) Sen. Lindsey Graham, (R) South Carolina:

"I'm disappointed in many ways that the Congress may be taken out of the game now because we're a public venue. I thought Yates and Klapper were good. I thought Sally Yates was an excellent witness. I thought Klapper provided insight to the public that we all need to know, you know. It's our nation here. So hearings like that are probably now off the table, and too bad."

5. SOUNDBITE (English) Sen. Lindsey Graham, (R) South Carolina:

"I have reason to believe there may be emails between the Clinton campaign and Democratic officials and the Department of Justice during the Obama administration. There is a problem here with committee jurisdiction. If there were emails from the Clinton campaign of the Democratic operatives to the Department of Justice during the Clinton email investigation, I want to know about it."

6. SOUNDBITE (English) Sen. Ted Cruz. (R) Texas:

"I don't think appointing a special counsel was necessary. But if one was going to be appointed, I think Bob Mueller is an excellent choice. I've known Bob for two decades. And he is a serious law enforcement professional. He's someone who has been appointed positions by both Republicans presidents and Democratic presidents. And he's earned the trust on both sides of the aisles, from Republicans and Democrats. He is a fair minded, serious prosecutor. He led the FBI with great distinction. And I'm confident that he'll investigate the matter and follow the facts wherever they may lead."

7. SOUNDBITE (English) Sen. John McCain, (R) Arizona:

"In the respect that there is a new revelation almost everyday, like this morning there's a new revelation that there was more communications between the Trump campaign and the Russians in that respect that there is a new revelation every few days."

(Reporter question off camera): "How does the appointment of a special counsel change that?'

(McCain): "I think it's very important, but that is the investigate the criminal activity. The Senate and the House have to investigate the aspects of Russian activity from the standpoint of sanctions against Russia, what we do to counter these attacks, and all the aspects of cyber warfare."

SOUNDBITE (English) Sen. Patrick Toomey, (R): Pennsylvania:

"Well my opinion of Bob Mueller is that he's terrific, completely unimpeachable in all respects and widely recognized as such by everybody. I never really was convinced that this is the best way to go. We have in the past when we've used special prosecutors and special counsels it hasn't always ended well. My view was always that the president should move quickly to get a completely unimpeachable leader of the FBI, preferably a Democrat so that there would be no doubt that that organization is being run by somebody who has no allegiance to Donald Trump."

Senate Republicans gave mixed reactions to the surprise announcement that the Justice Department has appointed former FBI Director Robert Mueller as a special counsel to oversee a federal investigation into possible collusion between Russia and the Trump campaign in 2016.

The Justice Department on Wednesday appointed former FBI Director Robert Mueller to lead the investigation.

Mueller will have sweeping powers and the authority to prosecute any crimes he uncovers.

Senate Intelligence Committee Chairman Richard Burr who considered the appointment as a good decision said that ousted National Security Adviser Michael Flynn will not honor a subpoena issued by a Senate committee looking into Russia's meddling in the 2016 presidential election.

Burr told reporters Thursday that Flynn's lawyer informed the panel he will not abide by a subpoena for private documents.

President Donald Trump lashed out at the appointment of a special counsel to investigate allegations that his campaign collaborated with Russia to sway the 2016 election, tweeting Thursday that it is "the single greatest witch hunt of a politician in American history!"

Reactions from Congress to Mueller's appointment were mainly positive, even though Republicans had dismissed an independent outside investigation as unnecessary and duplicative of what congressional committees already are doing.

Sen. John McCain of Arizona, the Republican chairman of the Armed Services Committee, says it's a "scandal" of Watergate proportions, and the only way to end it is to get out the full truth.

Republicans have largely stood behind Trump in the first months of his presidency as the FBI and congressional investigations into Russia's election meddling intensified.

But GOP lawmakers have grown increasingly anxious since Trump fired Comey, who had been leading the bureau's probe - and after Comey associates said he had notes from a meeting in which Trump asked him to shut down the investigation into the Russia ties of Flynn.

Washington - May 18, 2017

++SEPARATED BY BLACK++

1. SOUNDBITE (English) Sen. Richard Burr, (R) North Carolina:

"General (Michael) Flynn's lawyer said that he would not honor the subpoena and that's not a surprise to the committee. But we'll figure out on General Flynn what the next step, if any, is. But we're continuing on with a lot of interviews and through those interviews it leads us to additional document requests and additional individuals we'd like to talk to."

++BLACK FRAMES++

2. SOUNDBITE (English) Sen. Richard Burr, (R) North Carolina:

"(Former FBI) Director (James) Comey is a public citizen now. He's not constrained by investigations and we think the most important thing that Director Comey can contribute now is an understanding by the American people of what transpired. We happen to think that an open hearing in front of the intelligence committee is the right way for him to do it since we've worked so closely with him and we respect him so much."

++BLACK FRAMES++

3. SOUNDBITE (English) Sen. Lindsey Graham, (R) South Carolina:

"Clearly foreign governments could interfere in our election, they did this time. They may be more successful next time. So the shape and the scope of the congressional investigation I think has dramatically changed. I respect the decision. Mueller is a good guy. But one of the big losers here is the public because we're not going to hear from Comey now most likely. I hope we do. I want to hear about the conversation. I want to know the context of it. But now that you have a special counsel, maybe that's off the table."

++BLACK FRAMES++

4. SOUNDBITE (English) Sen. Lindsey Graham, (R) South Carolina:

"I'm disappointed in many ways that the Congress may be taken out of the game now because we're a public venue. I thought Yates and Klapper were good. I thought Sally Yates was an excellent witness. I thought Klapper provided insight to the public that we all need to know, you know. It's our nation here. So hearings like that are probably now off the table, and too bad."

++BLACK FRAMES++

5. SOUNDBITE (English) Sen. Lindsey Graham, (R) South Carolina:

"I have reason to believe there may be emails between the Clinton campaign and Democratic officials and the Department of Justice during the Obama administration. There is a problem here with committee jurisdiction. If there were emails from the Clinton campaign of the Democratic operatives to the Department of Justice during the Clinton email investigation, I want to know about it."

++BLACK FRAMES++

6. SOUNDBITE (English) Sen. Ted Cruz. (R) Texas:

"I don't think appointing a special counsel was necessary. But if one was going to be appointed, I think Bob Mueller is an excellent choice. I've known Bob for two decades. And he is a serious law enforcement professional. He's someone who has been appointed to positions by both Republicans presidents and Democratic presidents. And he's earned the trust on both sides of the aisles, from Republicans and Democrats. He is a fair minded, serious prosecutor. He led the FBI with great distinction. And I'm confident that he'll investigate the matter and follow the facts wherever they may lead."

++BLACK FRAMES++

7. SOUNDBITE (English) Sen. John McCain, (R) Arizona:

"I respect that there is a new revelation almost everyday, like this morning there's a new revelation that there was more communications between the Trump campaign and the Russians in that respect that there is a new revelation every few days."

(Reporter question off camera: How does the appointment of a special counsel change that?)

"I think it's very important, but that is to investigate the criminal activity. The Senate and the House have to investigate the aspects of Russian activity from the standpoint of sanctions against Russia, what we do to counter these attacks, and all the aspects of cyber warfare."

++BLACK FRAMES++

SOUNDBITE (English) Sen. Patrick Toomey, (R) Pennsylvania:

"Well my opinion of Bob Mueller is that he's terrific, completely unimpeachable in all respects and widely recognized as such by everybody. I never really was convinced that this is the best way to go. We have in the past when we've used special prosecutors and special counsels it hasn't always ended well. My view was always that the president should move quickly to get a completely unimpeachable leader of the FBI, preferably a Democrat so that there would be no doubt that that organization is being run by somebody who has no allegiance to Donald Trump."

++ENDS ON A SOUNDBITE++