By now it’s become pretty obvious that while many Republican members of Congress may be privately cheering for Sens. Bob Corker and Jeff Flake, they aren’t going to follow their lead and publicly break with the president or their party.

Politics is not all that complicated. It is a game of incentives. And, right now there is no incentive for Republicans to split from the President.

The fact is Republicans are getting a lot done on issues they care about. Conservative jurists picked for federal courts. Regulatory roll-backs. And, of course, the potential for tax cuts/reform.

What will making a speech like Flake’s or tweets like Corker’s get a GOP member of Congress? Perhaps some fawning coverage on Morning Joe, but also furious attacks at home from an angry base and most likely a primary challenge. Most Republican members figured out how to do this "Trump dance" in 2016. They distanced themselves from Trump when needed/promoted with replies like, "that’s not what I would have done,” or “that’s not how I would have said it"—and they then quickly pivoted to their own talking points.

The big question for 2018 is if this strategy will work in the midterms.

One thing that should scare Republicans—and make them think that the 2016 strategy may not be sufficient in 2018—is the enthusiasm gap. Back in 2016, Republicans were wary of Trump but they turned out and voted for him because they didn’t like the alternative and they were willing to accept the half-good versus the awful. Their ambivalence with Trump was outweighed by their disdain for Clinton. Two years later, they don’t have Obamacare repeal, a GOP-led Congress is getting little accomplished and the president continues to behave in a non-presidential way. With Hillary Clinton no longer on the ballot, the incentive to turn out is no longer quite as immediate or intense.

Meanwhile, Democrats, who were also less than thrilled about their nominee in 2016, are totally united in their disdain for Trump. The latest Survey Monkey poll shows Trump with a 92 percent disapproval rating among Democrats, with 83 percent say they strongly disapprove. Meanwhile, just half of all Republicans say they strongly approve of Trump.

What should worry Republicans even more is the fact that not only are independent voters sour on Trump (approval ratings of the president among this group are around 35 percent). But, they also are more strongly disapproving of the president than strongly approving. Among independents, 49 percent strongly disapprove to just 16 percent who strongly approve in the mid-October Survey Monkey survey. We spend a lot of time focusing on the fact that Republicans ultimately rallied to Trump’s side in 2016, but we don’t focus enough on the fact that he also carried independent voters by 4 points (46 to 42 percent).

Here’s why this matters: Angry people vote. Complacent people sometimes vote and sometimes don’t. And dispirited or disillusioned people stay home.

There is one other issue, however, that could split the GOP base and that’s the outcome of the Mueller investigation. Given how effectively Trump has demonized the investigation and coverage of it (FAKE NEWS, WITCH HUNT), no conclusion may be damaging enough to Trump for Republicans to turn on him. Moreover, if the final report is released before the midterms, it may end up giving a dispirited GOP base something to mobilize around in the way that Pres. Clinton’s impeachment goosed Democratic enthusiasm in 1998. However, the findings could be the final straw for reluctant Trump backers. But, what will they do about it? Will they actively split from the president? The party? What will they demand from their own representatives in Congress?

Forget all the stories about the “breaking up” of the GOP. There are really only two things that matter for GOP in the next year: the Midterms and Mueller. A disastrous 2018 and a damaging report could recalibrate Trump’s currently solid hold on his party.