Get breaking news alerts and special reports. The news and stories that matter, delivered weekday mornings.

Republicans have no real danger of losing control of the Senate in next year’s midterm elections. But the House is in play and its most at-risk GOP members have been quick to sound the alarm about President Donald Trump.

Serving as an early-warning sign for potential damage to the party is Rep. Carlos Curbelo (R-FL), who saw his South Florida congressional district vote for Hillary Clinton by 16 percentage points last year — the most for any GOP lawmaker seeking reelection in 2018.

Curbelo, the most endangered Republican, was already feeling the heat from constituents over his vote for the GOP health care bill when NBC News visited his district earlier this month and seems to be losing patience with the White House’ handling of fired FBI Director James Comey.

"If this is true, it is disconcerting and it opens up a new chapter of scandal and controversy in this country," Curbelo told NBC News Tuesday of reports that President Doanld Trump urged Comey to drop his investigation into ousted National Security Adviser Michael Flynn.

And Curbelo even raised the specter of impeachment in another interview. "Obstruction of justice is an impeachable offense. So that is an allegation we have to take very seriously," Curbelo told CBS4 Miami on Tuesday night. "That doesn't mean it happened, but if this story is accurate, it may have happened. Whatever the case is, we need to get the facts."

Let our news meet your inbox. The news and stories that matters, delivered weekday mornings. This site is protected by recaptcha

Curbelo last week was one of the first Republicans to call for a congressional Select Committee to investigate Comey's firing and the fallout from alleged Russian meddling in last year’s election.

His handling of the controversy could serve as canary in the coalmine for vulnerable Republicans more generally as they try to navigate the troubled political waters around Trump.

And he wasn’t the only one to break ranks on Comey.

Rep. Barbara Comstock (R-VA), who narrowly prevailed in one of the most hotly contested House elections last year and will face another tough one next year, put out a statement demanding an "independent investigation that the American people can trust.”

Another top Democratic target in next year’s midterms, Rep. Mike Coffman (R-CO), on Tuesday repeated a call he first made last week for a special prosecutor.

And Rep. Erik Paulsen (R-MN), whose suburban Minneapolis voted for Clinton by almost 10 percentage points last year, echoed the call for “an independent investigation that the American people can trust with confidence."

Rep. Darrell Issa (R-CA), a high-profile Republican from an area that is rapidly trending Democratic, called for a special prosecutor even earlier than others.

Even some Republicans from safer districts are now calling for a special prosecutor, like Rep. Adam Kinzinger (R-IL), whose suburban Chicago district has not been held by a Democrat since the 1990s.

“This is very new for me to say it, I’ve been saying let’s let the House and Senate committees work their will,” he said on MSNBC Wednesday. “But the accusation is serious enough that you couple that with what we’ve known in the past... I do think we need independent eyes to figure out what happened.”