So now we have us some candidates, on the Republican side. Who’s the big kahuna? Jeb Bush? He keeps getting called front-runner, and I suppose he is, even though the polls sometimes say otherwise. Scott Walker? Certainly a player. Rand Paul? Pretty bad rollout, but he has his base. The youthful, advantageously ethnicized Marco Rubio? Some as-yet-unannounced entrant who can hop in and shake things up?

Each has a claim, sort of, but the 800-pound gorilla of this primary process is none of the above. It’s the same person it was in 2008, and again in 2012, when two quite plausible mainstream-conservative candidates had to haul themselves so far to the right that they ended up being unelectable. It’s the Republican primary voter.

To be more blunt about it: the aging, white, very conservative, revanchist, fearful voter for whom the primary season is not chiefly an exercise in choosing a credible nominee who might win in November, but a Parris Island-style ideological obstacle course on which each candidate must strain to outdo his competitors—the hate-on-immigrants wall climb, the gay-bashing rope climb, the death-to-the-moocher-class monkey bridge. This voter calls the shots, and after the candidates have run his gauntlet, it’s almost impossible for them to come out looking appealing to a majority of the general electorate.

You will recall the hash this voter made of 2012. He booed the mention of a United States soldier during a debate because the soldier happened to be gay. He booed contraception—mere birth control, which the vast majority of Republican women, like all women, use. He lustily cheered the death penalty. He tossed Rick Perry out on his ear in part because the Texas governor had the audacity to utter a few relatively humane words about children of undocumented immigrants. He created an atmosphere in which the candidates on one debate stage were terrified of the idea of supporting a single dollar in tax increases even if placed against an offsetting $10 in spending cuts.

He is a demanding fellow. And he is already asserting his will this time around. Why else did Bush endorse Indiana Governor Mike Pence’s religious freedom bill in an instant, only to see Pence himself walk the bill back three days later? Bet Jeb would like to have that one back. But he can’t. The primary voter—along of course with the conservative media from Limbaugh and Fox on down—won’t permit it.

Now, as it happens, some of these candidates come to us with a few serious and unorthodox ideas. We all know about Rand Paul and his ideas about sentencing reform and racial disparities. He deserved credit for them. He was a lot quicker on the draw on Ferguson than Hillary Clinton was. But how much do we think he’s going to be talking up this issue as the Iowa voting nears? Time might prove me wrong here, but Paul has already, ah, soul-searched his way to more standard right-wing positions on Israel and war, so there’s reason to think that while he might not do the same on prison issues, he’ll just quietly drop them.

More interesting in this regard is Rubio. I read his campaign book not long ago, along with five others, for a piece I wrote for The New York Review of Books. Rubio’s book was the best of the lot by far. It was for the most part actually about policy. He put forward a few perfectly good ideas in the book. For example, he favors “income-based repayment” on student loans, which would lower many students’ monthly student-loan bills. It’s a fine idea. The Obama administration is already doing it.

Beyond the pages of the book, Rubio has in the past couple of years staked out some positions that stood out at the time as not consisting of fare from the standard GOP menu. He’d like to expand the Earned Income Tax Credit to more childless couples. Again, there are synergies here with the current occupant of the house Rubio wants to move into—the Obama administration is taking up this idea.

Now, there is to be sure another Rubio, one who’d feel right at home on Parris Island. He is apparently now the quasi-official blessed-be-the-warmakers candidate, with his reflexive hard lines on Iran and Cuba. Along with Senate colleague Mike Lee of Utah, he also has put forth a tax plan that would deplete the treasury by some $4 trillion over 10 years—for context, consider that George W. Bush’s first tax cut cost $1.35 trillion over a decade—in order that most of those dollars be placed in the hands where the Republicans’ God says they belong, i.e., the 1 percent of the people who already hold nearly half the country’s wealth.

I think it’s a safe bet that we’ll see the neocon Rubio and the supply-side Rubio out on the stump. But the Rubio who wants to make life better for indebted students and working-poor childless couples? Either we won’t see that Rubio at all, or we will see him and he’ll finish fourth in Iowa and New Hampshire and go home. You can’t be a smart candidate in a party that wants to be stupid.

Might I be wrong about the primary voter? Sure, I might. Maybe the fear of losing to Hillary Clinton and being shut out of the White House for 12 or 16 consecutive years will tame this beast. But the early signs suggest the opposite.

After all, how did Scott Walker bolt to the front of the pack? It wasn’t by talking about how to expand health care. It was by giving one speech, at an event hosted by one of Congress’ most fanatical reactionaries (Steve King of Iowa), bragging about how he crushed Wisconsin’s municipal unions. That’s how you get ahead in this GOP. I’d imagine Rubio and Paul and the rest of them took note.