So this is where the GOP civil war begins.

Asked by The Huffington Post about ending the filibuster, [Hatch] was blunt.

“Are you kidding?” he said with some vehemence. “I’m one of the biggest advocates for the filibuster. It’s the only way to protect the minority, and we’ve been in the minority a lot more than we’ve been in the majority. It’s just a great, great protection for the minority.”

He’s not alone in that opinion. Per New York mag, Lindsey Graham said ending the filibuster was a “horrible, terrible idea” when asked about it a few days ago. That makes two Republican votes in the Senate for protecting the Democrats’ power to block Trump’s initiatives — and, importantly, Hatch and Graham are both insulated (somewhat) from the usual grassroots pressures that might force them to change their minds. Hatch is still on track to retire in 2018; even if he changed his mind and ran again, Trump’s favorability in his home state of Utah was poisonous all year and Hatch is an institution there. Graham is more susceptible to a primary challenge since he’s likely to run again in a state that voted for Trump twice, once in the primary and the other in the general election, but his seat’s not up for four more years. And Graham has proved himself wily in beating back threats from right-wing populists. Border hawks have been clamoring for 10 years for someone to primary him, and that’s gone nowhere twice. Unless Trump is prepared to campaign against a member of his own party in 2020, when he himself will be busy campaigning for reelection as president, Graham doesn’t have much to worry about.

So let’s do some second-grade math. The GOP will have 52 seats in the Senate after Louisiana’s run-off election next month. To eliminate the filibuster for Supreme Court nominations or for legislation, they need a simple majority of 51 votes. Without Hatch and Graham, they’re at 50; in that case, Mike Pence would break the tie and supply the 51st vote. If the lose even one more senator, though, there’s no tie. Their attempt to nuke the filibuster will fail outright. (It’s possible but unlikely that Democrat Joe Manchin, from deep red West Virginia, would betray his own caucus by voting with the GOP to take their power away. If he’s going to do that, though, he might as well switch parties.) Is there one more vote to save the filibuster among those 50 Republicans? Well … yeah, probably. Eighty-year-old John McCain just won reelection and is now in his final term (I think). He’s an old-school Senate traditionalist and a Graham ally, and he spent the final few weeks of his campaign this year vowing that the Senate GOP would unite to block President Hillary’s court picks. He has nothing to lose by sticking it to Trump and siding with Hatch and Graham on the filibuster. He might even enjoy paying back Trump for his nasty comment about McCain’s Vietnam service last year.

Those three would be enough to hand victory to the Democrats, but someone like Rand Paul who’s eager to assert his own check on Trump’s executive power might flip too. So might some of the centrists like Murkowski and Collins. The effort to nuke the filibuster, at least for legislation, could end up failing badly. And President Trump isn’t going to like that once Democrats start using their power to bog down his agenda. Some parts of O-Care can be undone via reconciliation, which requires just 51 votes, but not all of them can. An infrastructure bill that leans too far towards Republican spending priorities might be filibustered as well. A narcissist who ran and won as a can-do strongman who’s ready to get America moving again isn’t going to understand why his own party insists on siding with the Democrats’ right to obstruct rather than with his right to follow through on his alleged electoral mandate. And he’s going to take that case to his voters. And that’s when the party ends up at each other’s throats.

What you might end up seeing here, as a sort of compromise, is Republicans agreeing to nuke the filibuster for SCOTUS appointments while keeping it in place for legislation. Which may not mean much in practice: The judges on Trump’s list of potential nominees are all well qualified and would probably get 60 votes for cloture anyway. But Chuck Schumer, sensing the tension within the GOP over the filibuster, might have an incentive now to go to the mat and try to filibuster Trump’s first nominee, just to put McConnell in a jam where he has to decide whether to risk angering Hatch et al. by ending the SCOTUS filibuster or to risk angering Trump by siding with Democrats in preserving it. Get ready.

Here’s Mitch the Knife in July 2013, a few months before Reid and the Democrats ended the filibuster for non-SCOTUS nominees, warning that a majority leader who takes the minority’s power away will have as his epitaph that he ended the Senate as we know it.

Update: Unsurprisingly, Hatch and Graham sound more open to ending the filibuster for SCOTUS nominees than for legislation.

But when specifically asked by TWS if Republicans should remove 60-vote requirement for Supreme Court nominees if Democrats block a new nominee, Hatch didn’t rule it out. “We’re going to get a new Supreme Court justice,” Hatch replied. “Just count on it.”…

Senator Lindsey Graham of South Carolina expressed opposition to changing the filibuster, but he too didn’t rule it out if a Supreme Court nominee is blocked. “I’d like to keep the Senate the Senate if at all possible,” Graham told TWS.

“The last thing I want to do is behave like Harry Reid when it comes to the Senate. I hope that Senate Democrats will understand that President Trump has the same rights as President Obama,” Graham said. “I voted for both of Obama’s nominees because I thought they were qualified even though I wouldn’t have chosen them. And I quite frankly expect the same constitutional courtesy to this president. You can have a challenging hearing. You can do all the things the nominating process is about. But I hope that our Democratic friends—I’m asking them no more than I’m asking myself.”