Senate Majority Leader Mitch McConnell (Chip Somodevilla/Getty Images)

Should Republicans in Congress get on board with a growing number of GOP primary voters and join Team Trump?

Some say no way, others say it's the only chance they've got to beat Hillary Clinton.

But one thing's for certain: Donald Trump's increasingly likely nomination is dividing the Republican Party and threatening to drive its members into an identity crisis about the party's future.

Leading the debate on both sides are Republican members of Congress. In the days before Super Tuesday's 11-state GOP primary, some have very publicly come out either in support of Trump or against him. Which side the majority of Republicans in the House and Senate ultimately choose could be a major factor in Trump's success -- and their own -- come November.

Here are five very different groups that Republicans in Congress fall into right now on whether to support Donald Trump.

1. Donald Trump's my man

Sen. Jeff Sessions (R-Ala.) endorsed Republican presidential candidate Donald Trump's White House bid during a joint appearance in his home state. (Reuters)

The folks in this camp have decided to jump wholeheartedly into Trump's pitch for voters. Not only is he the GOP front-runner; he is the best candidate for the job, they say.

"This isn’t a campaign; this is a movement," said Sen. Jeff Sessions (R-Ala.), who on Saturday became the first sitting U.S. senator to endorse Trump.

Before Sessions, Rep. Chris Collins (R-N.Y.) became the first sitting member of Congress to endorse Trump.

Collins told The Fix he simply thinks Trump is the strongest in the field on national security and job creation. "He's the man to do it," Collins said.

2. If you can't beat him, join him

In this group, we have the pragmatists. As early as mid-February, at least one member of Congress, Rep. Duncan Hunter (R-Calif.), saw the writing on the wall that Trump is the most likely Republican candidate to win the nomination and decided it'd be more prudent to join forces with him rather than against him.

Hunter's chief of staff, Joe Kasper, explained it like this to The Fix: "You have to stop talking nonsense and saying disparaging things about the guy who ultimately is more likely than not to be the Republican nominee."

3. I'll support him if he's the nominee …

This is where the majority of Republicans in Congress stand -- in public at least. It's the establishment talking point that Republicans are better united around one of their own than divided facing Hillary Clinton.

House Speaker Paul D. Ryan (R-Wis.), House Majority Leader Kevin McCarthy (R-Calif.) and leading Senate Republicans like Sen. John McCain (Ariz.) have all said they'll support Trump if he becomes the nominee -- despite the fact that doing so opens them up to attacks from Democratic challengers.

4. … Unless I'm a vulnerable Senate Republican

Take one look at this ad running in Arizona against McCain and you can see why Senate Republicans are worried that, with Trump at the top of the GOP's ticket, they won't be able to hold onto their majority in November.

In it, McCain's likely Democratic challenger, Rep. Ann Kirkpatrick (D-Ariz.), repeatedly ties McCain to a slew of Trump's most controversial comments, like supporting waterboarding and even questioning McCain's war hero status. It is, quite frankly, brutal. And Senate Republicans know they can expect ads like these to pop up against the eight or so other Republican senators up for reelection in swingy or blue states in November.

The situation could be so dire, the New York Times reports, that Senate Majority Leader Mitch McConnell (R-Ky.) has told vulnerable Senate Republicans they can break with Trump if he's the party's nominee -- even apparently suggesting they run negative ads about Trump to distance themselves from the controversial presidential candidate.

5. No way, now how

Then there's this from freshman Sen. Ben Sasse (R-Neb.), one of the more conservative members in the Senate. On Sunday, Sasse said if Trump gets his party's nomination, Republicans should directly challenge him by looking for an independent candidate.

"Mr. Trump’s relentless focus is on dividing Americans and on tearing down rather than building back up this glorious nation," Sasse wrote in a detailed Facebook post explaining his decision.

So far, he's the only Republican in Congress to publicly call for actively undermining his party's likely presidential nominee.

But the divisions among Republicans in Congress on what to do about Trump suggest more could soon join him.

These are the options these Republicans in Congress face.