But primary results this past week have forced Senate Republicans to come to terms with the fact that the man who could cost them control of the chamber -- and for some of them, their jobs -- may well be their party's nominee for president. Such a scenario leaves most of the 54 Senate Republicans with an impossible decision: Do they support the presidential candidate Republican voters chose, even though it may cost some of them their jobs? Or do they go on the record opposing the likely will of the voters and potentially hampering their party's hopes of reclaiming the presidency?
There's nearly as many answers to that as there are GOP senators. The Washington Post surveyed Senate Republicans this past week to ask them one question: Will you support Donald Trump if he is the GOP nominee for president?
Not everyone got back to us -- perhaps a reflection of this being a question they'd rather ignore -- so we scraped the senators' comments in media reports as well. Here's what we found:
31 say yes, with most saying at least he's better than Clinton (and some leaving themselves wiggle room)
By our count, the slightest majority -- 31 of 54 -- have indicated they will support the Republican nominee even if it's Trump.
There's one senator so far, Sen. Jeff Sessions (Ala.), who has endorsed Trump. Another 25 have specifically said they will support whoever is the nominee. They include party leaders like Senate Majority Leader Mitch McConnell (Ky.), the Senate's No. 2, Sen. John Cornyn (Tex.), and Sen. Orrin Hatch (Utah), the most senior Republican senator. Most of the senators in this category say they'll support Trump for one simple reason: He's better than Hillary Clinton.
"Any of the candidates we have on their worst day, is better than Senator Clinton on her best," Sen. Thom Tillis (N.C.) said.
That doesn't mean Senate Republicans' support for Trump is a done deal. About a half-dozen senators who indicated or appeared to indicate they'll support Trump's nomination also expressed serious reservations about it -- especially after Trump took several days to denounce support from a former Ku Klux Klan leader. Several of their comments leave wiggle room for them to back out.
Sen. Rob Portman (Ohio), who is in a tough reelection battle back home, said he intends to support the nominee "unless something crazy happens." And as we've written before, Trump's principal danger to Republicans who share the ballot with him is that he's anything but predictable.
Some, like Sen. Ron Johnson (Wis.), who is in a fight for his political life this year, appeared genuinely undecided about what to do. "I go to bed every night praying that our nominee is a person of integrity, intelligence, ideas, and courage," he said, before deciding over the weekend he would support whoever is the nominee.
22 aren't sure -- or don't want to say
Next come the undecideds, which by our count include 23 GOP senators -- nearly half the caucus.
Some, like Sen. Susan Collins (Maine) appear genuinely undecided: "I'm just going to step back and watch for awhile and see how it unfolds. ... This has been the strangest election that I've seen in all my years in politics."
Others appear to be leaning toward a decision. Sen. Bill Cassidy (La.) has said he could work with a President Trump but hasn't indicated whether he would support him if he were the nominee. Sen. Tim Scott (S.C.) has expressed doubts about Trump: "Any candidate who cannot immediately condemn a hate group like the KKK does not represent the Republican Party and will not unite it."
But it's a safe bet that most senators in this group are holding out hope Trump won't be their nominee -- rendering the need to go on the record about whether to support him moot.
"That's not going to happen," a spokesman for Sen. Mike Lee (Utah) told The Fix when talking about the possibility of a Trump nomination.
About four or five senators haven't gone on the record -- to The Fix or anywhere else -- about what they'd do. And that's after The Fix repeatedly attempted to get their comments over the course of the last several days.
1 senator says no way
Sen. Ben Sasse (Neb.) became the first sitting senator (and so far only) to publicly say he would not support Trump, citing the candidate's divisiveness.
"I sincerely hope we select one of the other GOP candidates, but if Donald Trump ends up as the GOP nominee, conservatives will need to find a third option," Sasse wrote on Facebook on the eve of Super Tuesday last week.
Whether more senators join him is an open question. Things aren't likely to get easier for the senators in the coming days and weeks, especially if the nominating process drags out until July, where some GOP leaders are openly considering a contested convention to stop Trump.
We'll keep you updated on what changes. Until then, if you don't agree with where The Post put your senator or see a new and different comment from that senator, let us know.
Mike DeBonis and Paul Kane contributed to this report.