WASHINGTON — Democrats will need at least 17 Republican senators to break ranks to convict President Donald Trump after he was impeached Wednesday, a high hurdle that would require changing the minds of lawmakers who have stood behind him.
That is more than the 10 House Republicans who broke with Trump in the most bipartisan impeachment vote in American history, which charged him with incitement of insurrection.
Even as Senate Majority Leader Mitch McConnell, R-Ky., publicly flirts with supporting a conviction for Trump's role in the deadly attack on the Capitol that targeted him and his staff, getting a third of the GOP Senate caucus to vote to convict will be no easy task.
Trump maintains high approval ratings and a passionate following among some Republican voters. He still held a 71 percent approval rating among GOP voters in a Quinnipiac University poll taken after the riot.
Convicting Trump would allow the Senate to bar him from ever seeking elected federal office again, immediately reshaping the 2024 Republican presidential primaries, in which he could otherwise be a candidate.
But impeachments are inherently political affairs, and even a trial that takes place after Trump's term expires would be rife with political calculations, both for senators who could seek re-election and for those who might make bids for the presidency themselves.
Republicans control the Senate now, but Democrats are set to take over after President-elect Joe Biden takes the oath of office on Jan. 20. A drawn-out trial could impede Biden's early days in office, which may be a feature or a bug for different senators.
Once the Senate seats all the newly elected members, the chamber will split 50-50, and incoming Vice President Kamala Harris will cast the tiebreaking vote.
A handful of Republican senators have already criticized Trump and signaled that they would be open to support conviction. But to secure a conviction, more votes would be needed, and supporters would be likely to look to senators who are retiring or other longtime members who are viewed as institutionalists.
That's likely to be difficult.
The outcome could come down to McConnell, who has a deep reservoir of trust within his caucus. If he were to back conviction, he could lead more reluctant senators to follow suit.
But for now, he says he is undecided.
"I have not made a final decision on how I will vote, and I intend to listen to the legal arguments when they are presented to the Senate," he wrote to colleagues Wednesday afternoon, according to a spokesman.
McConnell and Trump have a complicated relationship — polar opposites in personality, staunch allies in some policy objectives. McConnell broke with Trump last week, making an impassioned plea to reject Trump's efforts to overturn the election.
McConnell is in no rush to hold a trial; his office indicated that he won't bring the Senate back before Tuesday. That means the trial is all but guaranteed to conclude under a Biden presidency in a Democratic-controlled Senate.
The factions in an impeachment trial
Liam Donovan, a lobbyist and former Senate Republican campaign operative, said McConnell's apparent willingness to consider conviction "suddenly turns an unthinkable break with Trump into something that is very much in play."
"I remain a skeptic, if only because 17 is still a daunting number," Donovan said. "McConnell's imprimatur alone would carry a ton of weight."
Sen. Mitt Romney of Utah is seen as the most likely Republican to support conviction, as he was the only one who voted to remove Trump from office in the first impeachment trial last year. In addition, Sen. Lisa Murkowski of Alaska and retiring Sen. Pat Toomey of Pennsylvania have said Trump should resign. Centrist Sen. Susan Collins of Maine could be a supporter of conviction, as could Sen. Ben Sasse of Nebraska.
After those five, it gets trickier.
One group could be octogenarian institutionalists who may be eyeing retirement: Chuck Grassley of Iowa, Richard Shelby of Alabama and James Inhofe of Oklahoma.
Other targets may be senators who have been critical of Trump for trying to overturn the election, including Rob Portman of Ohio and Bill Cassidy of Louisiana. Retiring Sen. Richard Burr of North Carolina is another possibility.
That still wouldn't be enough.
Two wild cards are Mike Lee of Utah and Rand Paul of Kentucky. They have presented themselves as "constitutional conservatives" and were unwilling to vote with Trump to overturn the election even before the riot breached the Capitol. But both have been very supportive of Trump, and Paul faces voters in deep-red Kentucky next year.
The critical question, then, is how hard McConnell would push fellow Republicans to vote to convict — and how many would be willing to follow him. Two members of his leadership team, Roy Blunt of Missouri and John Thune of South Dakota, face re-election next year and would risk primary challenges.
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Two others, Joni Ernst of Iowa and Todd Young of Indiana, have more time before they face voters again and might be more inclined to follow McConnell.
McConnell's position might also command votes from rank-and-file senators like Kevin Cramer of North Dakota and Mike Rounds of South Dakota. But the highly charged politics and the deep fracture shaking the GOP may scramble any typical calculation.
A senior Republican aide said the votes will probably be there to convict Trump if McConnell is on board. But a former Senate GOP staffer said he may need to work for it.
"If McConnell were to say 'I'm voting to convict' but this is a conscience vote, it's still hard to get to 17. He would need to work it," said the former aide, who maintains relationships with ex-colleagues and offered a candid assessment on condition of anonymity. "This is a situation where you could have an easy 10 votes. But 11 to 17 is probably harder."