"I think it's terrible. I don't agree with any of it," Francis Rooney said. "But they're derogating the work of our paid foreign service."
"If we abandon the Kurds, ISIS will come back and if there's an attack here or against our allies, President Trump owns it," the Republican senator said.
"This is a complete and utter national security disaster in the making and I hope President Trump will adjust his thinking," the Republican senator tweeted.
Donald Trump and his supporters have repeatedly argued that the impeachment inquiry is overtly "partisan" and a "witch hunt."
Ronna McDaniel, GOP chairwoman and niece of Mitt Romney, has accused Joe Biden's son Hunter of nepotism in his business dealings with Ukraine.
Trump gave Turkey the green light to invade northeastern Syria after a phone call with Turkish President Erdoğan last Sunday.
"He doesn't try to do it covertly," Senator Kevin Cramer of North Dakota told CNN.
"I don't understand how a president that claims he's the toughest President ever would do such a weak move like this," Representative Adam Kinzinger said.
"No foreign government should ever be involved in a U.S. election in any way," Representative Adam Kinzinger told Fox News.
The governor says he is "skeptical" of the impeachment inquiry into President Trump's dealings with Ukraine.
"It is horrifying for President Trump to ask foreign governments to interfere in a U.S. election," Chris Truax, RRL's legal adviser, told Newsweek.
Mitt Romney, Susan Collins and Rob Portman are part of a small group of GOP Senators who have pushed back against Trump's actions and remarks.
"You'll have a very Democratic Senate next year," former Massachusetts Governor Bill Weld said.
"By abandoning the Kurds we have sent the most dangerous signal possible – America is an unreliable ally," the Republican senator from South Carolina argued.
"I think he honestly believes his political self-interest is the nation's interests," the former Hewlett-Packard CEO said of President Donald Trump in an interview for the "Recode Decode" podcast.
"We were devoted to the Constitution," Linda Chavez said. "And what I see happening now is people who are absolutely abrogating their duty.
"But I wouldn't be surprised if it's even more than that," Representative Brendan Boyle said.
Michael J. McDonald told the 2020 Democratic primary candidate that Nevada was "Trump country" a year after Democrats gained a Senate seat in Nevada.
"Republicans have a problem, particularly in college educated suburban areas," Ari Fleischer said.
Retired Lieutenant Colonel Ralph Peters said Trump's weekend Twitter tirade shows he is a "frightened, frightened man."
Florida's Republican Party is rallying around President Donald Trump's 2020 reelection campaign, with the state GOP chairman rejecting calls to cancel a primary he says Trump will win in a "blowout."
"I have visited nations ravaged by civil war.@realDonaldTrump," GOP Rep. Adam Kinzinger tweeted. "I have never imagined such a quote to be repeated by a President."
Trump has no shortage of opponents, but here are some Republicans who have made their opposition known.
The New Mexico Republican Party was forced to rebuke a Christian conservative congressional candidate for making "untrue statements" in advertisements targeting his opponent's stance on abortion.
"The politics of it will get worse and worse for Trump," Mike Murphy said.
Governor Bill Weld accused President Trump of "treason" over his phone call with Ukrainian President Volodymyr Zelensky on "Morning Joe."
The former secretary of state called on the White House to release the transcript of the suspect phone call, calling it the only way to discover the truth.
"I wanted to make the case to this politician that Trump has trampled on the constitution we both swore to protect for long enough," Jason Hurd told Newsweek.
"The irony is that in 2016, candidate Trump complained about 'rigged' primaries," John Avlon pointed out.
The two Republicans are looking to flip the 26th Congressional District seat, which is currently occupied by Democratic Representative Debbie Mucarsel-Powell.