After the Senate floor had been cleared of rioters on Jan. 6, Sen. Lindsey O. Graham (R-S.C.) stood up to push his peers to move forward with certifying Joe Biden’s election as president — the ceremonial act that the rioters had hoped to derail.

“It’s not going to do any good, it’s going to delay, and it gives credibility to a dark chapter of our history,” an emotional Graham said. Those who sought to object to the election results had the right to do so, he continued. But “I just think it’s a uniquely bad idea to delay this election,” he said.

“Trump and I, we’ve had a hell of a journey. I hate it to end this way. Oh my God, I hate it,” Graham said. “From my point of view, he’s been a consequential president, but today, first thing you’ll see. All I can say is count me out. Enough is enough.”

That “enough is enough” has been interpreted as Graham washing his hands of Trump, but in context it’s clear that he’s talking about the last-ditch, futile effort to derail Biden’s inauguration two weeks later.

Graham’s journey with Trump was, in fact, a rocky one, but it culminated with Graham largely folding into Trump’s worldview. Over the course of Trump’s presidency, this development was considered unexpected, given that Graham had once tweeted this:

Over the past few days, Graham has again risen to the defense of the former president, arguing more than once that Trump had an undeniable role in the Republican Party. In an interview with Bloomberg News, though, he showed how his 2016 tweet and his current advocacy for Trump overlap.

“I think it would be a disaster for the Republican Party if we just didn’t acknowledge the fact that Donald Trump’s the most popular person in the party,” Graham said. “The ‘America First’ agenda is well-respected. If you tried to run him out of the party, he’d take half the party with him.”

As NBC’s Benjy Sarlin pointed out over the weekend, this appears to reflect a consistent throughline of Graham’s relationship with Trump: If Trump took over the party, it would become dangerous to extricate him. If Trump were rejected in 2016, some of the enthusiasm he engendered on the right might have faded, but the party probably would have continued on a consistent path. With his nomination and subsequent presidency, much more of the base bought in to his vision of the party and his leadership.

Trump was never a loyal Republican, a concern that in 2015 prompted the party to demand he sign a document pledging he wouldn’t run as an independent. Were he to walk away, he could fracture the GOP.

The size of that possible fracture is an important question. If Trump were to demand his base reject the Republican Party but only 1 or 2 percent did so, the party could shrug at the threat. If, as Graham suggested, he would get half of Republicans to look elsewhere, that would be an existential problem.

The most direct polling aimed at answering that question comes from a Suffolk University survey conducted in February for USA Today. It found that a Trump-backed third party would lead to about half of Republicans and Republican-leaning independents joining his effort, with a quarter sticking with the GOP and the last quarter being undecided about what they would do. That, right there, seems to confirm Graham’s point.

But it is not necessarily that clear-cut. That poll was conducted two weeks after Trump’s second impeachment trial, a period in which defense of Trump was conflated with right-wing loyalty. There are some suggestions that Trump’s hold on the party has faded since then, including polling from NBC News conducted last month.

Asked whether they considered themselves more supporters of Trump or the Republican Party, half of Republicans and Republican-leaning independents said that they were more supporters of the party — the highest measure on that question since NBC began asking.

That, too, is a rough evaluation of the question. We get more detail from an interesting bit of analysis conducted by the polling firm Fabrizio Lee, one of Trump’s own pollsters. In March, the firm divided the Republican Party into what it called five “tribes,” ranging from never-Trump Republicans to the “Infowars GOP” — that wing of the party that supported Trump and false information.

Most of the party fell into the “Trump boosters” and “diehard Trump” categories. The former expressed support for Trump but were more supportive of the party. The latter were strong Trump supporters, but without an embrace of false information. The fifth tribe was made up of the “post-Trump” Republicans, a group that liked Trump but was ready to move on.

Asked whether they supported the party or Trump more, you can see how each group differs. Because the groups aren’t the same size, though, it’s important to note that the party overall was about evenly divided between loyalty to Trump and loyalty to the GOP. A quarter of the party falls into that “diehard Trump” group that’s more supportive of Trump, while only about 15 percent fall into the “never Trump” group that prefers the GOP.

On the question of who should lead the party, there was more uniform opinion. Most Republicans think that Trump should continue to be the party’s leader, despite indifference from the more skeptical Republican groups.

Gallup polling also captured a sense that Republicans seemed increasingly eager for another option in national politics. In August, 4 in 10 Republicans supported a third major political party. In February — again, just after the impeachment trial — 63 percent did.

But this polling is speculative, asking people to evaluate what they might do if Trump did leave the GOP. Were that scenario to unfold, it’s not clear that most Republicans would actually refrain from supporting or voting for party candidates when the alternative is an almost-certain victory from Democrats.

Most Republicans view Democrats not as political opponents but as enemies, an alarming finding from a poll earlier this year. Would Trump loyalists simply cede the field to Democrats if the best bet to beat the left was a Republican candidate?

Put another way, it’s easy to see why a Republican Party so centered on Trump’s personality would embrace the idea of walking away from a party that they had long viewed with some skepticism. But that’s different from actually doing so.

One factor worth considering is how the GOP fared during Trump’s political tenure. In 2016, Trump narrowly defeated Hillary Clinton in the electoral college in an unusually low-turnout cycle. Clinton received about as many votes as Barack Obama had four years earlier; Trump got about 3 percent more votes than Mitt Romney did in 2012.

In 2018, without Trump on the ballot, the Republican Party got hammered. Republican House candidates received about 27 percent more votes that year than they had in 2014, a year in which they did particularly well. Democratic House candidates, though, received 70 percent more votes in 2018 than they had in 2014. Even with Trump in the White House and supporting the party, the GOP wasn’t able to fend off a midterm wave.

Last year, Trump got 18 percent more votes than he had in 2016, an accomplishment he has used repeatedly as faulty evidence that he should have won. But the number of votes Biden earned was up 23 percent more than what Clinton had gotten.

It’s also interesting to compare how the presidential candidates did relative to House candidates. In 2008, John McCain got 15 percent more votes than did Republican House candidates; Obama got about 7 percent more. In 2012, Romney got 5 percent more votes than Republican House candidates, while Obama got 11 percent more. In 2016 and 2020, the Democratic candidates got 7 percent and 5 percent more votes, respectively. In 2016, Trump underperformed House candidates. Last year, he got only 2 percent more votes.

These are again vague ways of assessing Trump’s influence, but the numbers don’t suggest that Trump’s role as leader of the Republican Party helped much in 2018. It probably hurt; Democratic turnout that year and in 2020 was certainly driven to a significant extent by opposition to Trump.

It’s unclear whether Trump turned out Republican voters in 2016 and 2020 who otherwise would not have voted, but if he did, it was not enough in either contest to earn more votes than the Democrats.

That’s the corollary to Graham’s point. After Romney lost in 2012, the GOP embarked on an effort to figure out how to prepare for future elections. A report created by a party working group recommended better outreach to non-White voters — a strategy Trump tossed in the trash. (Figuratively, if not literally.) Preliminary analysis from the voter data firm Catalist released this week shows what toll that might have taken: 6 in 10 new voters in 2020 were younger than 45 and about 6 in 10 of the two-party votes they cast (that is, votes for either Biden or Trump) were cast for Biden.

It’s not clear how the Republican Party, in its current composition, could lure a significant number of those voters. But it is clear that young people in particular are skeptical of Trump. In a January Post-ABC News poll, more than half of those younger than 40 said they strongly disapproved of Trump’s presidency.

So where do we land? Polling suggests that Trump forming a new party could pull some Republicans away. Whether that means that Republican candidates at the nonpresidential level actually lose campaign contributions or votes isn’t clear; to paraphrase something the political scientist Julia Azari has argued, partisanship is stronger than parties.

Continuing to focus on Trump does, however, mean that the party intends to remain committed to a leader who never won the popular vote for president, who left office after four years with his party having lost control of both chambers of Congress and who was unable to increase his party’s appeal to the younger voters who make up an increasing percentage of the electorate.

Graham’s prediction about the party being cut in half by Trump is questionable. His prediction about the party being destroyed relative to the form it took in 2016, though, is probably more defensible.