Joe Donnelly. Photo: Paul Morigi/Getty Images

The Republican Party may need Democratic help to overcome their legislative impotence, and realize their top legislative priority — and Democrats just might give it to them.

Last week, the GOP leadership unveiled the party’s much-belated framework for tax “reform.” Like every other tax bill drafted by Republicans in recent months (or years, or decades), President Trump’s official plan is a blueprint for radically increasing the deficit and exacerbating economic inequality. In 2018, the Trump tax cuts would deliver 53 percent of their benefits to the top one percent of earners; by 2027, the one percent’s share of Uncle Sam’s lost revenue would climb to 80 percent, according to the nonpartisan Tax Policy Center.

Enthusiasm for regressive fiscal policy is, of course, the tie that binds congressional Republicans. But unlike the party’s previous tax plans, Trump’s final framework includes enough details to widen internal divisions: To partially offset the cost of delivering mammoth returns to the GOP’s top investors, Trump’s plan would eliminate the state and local tax deduction (SALT) — a loophole much beloved by upper-middle-class households in states with high income-tax rates (which, not coincidentally, are predominately blue ones). That measure — combined with the plan’s abolition of the personal and dependent exemptions — would leave many number of suburban families paying a higher tax bill, even as plutocrats pocket a break of over $700,000 next year, alone.

This has, predictably, provoked a sharp backlash among blue-state Republicans in the House. The response has been so fierce, the administration is already signaling openness to leaving SALT in place. But without SALT’s abolition, Trump’s plan would add $3.6 trillion to the deficit over the next decade, instead of $2.4 trillion — and the party’s few sincere deficit hawks have already mandated that the plan increase the debt by no more than $1.5 trillion. Meanwhile, the Freedom Caucus is suggesting that it won’t accept tax cuts any smaller than the ones currently on the table.

All of which is to say: It is going to be hard for Mitch McConnell to hammer out a final tax bill on which libertarian die-hards like Rand Paul, politically invulnerable deficit scolds like Bob Corker, and purple state moderates like Susan Collins can all agree. And after a trio of Republican defections killed the party’s every attempt to repeal Obamacare, the White House is eager to increase McConnell’s margin for error.

Thus, in recent weeks, Trump has sought to pressure red-state Democrats to get behind his “middle class tax cut.” The president has given especially keen attention to winning over Joe Donnelly of Indiana, Heidi Heitkamp of North Dakota, and Joe Manchin of West Virginia, and has held rallies for his agenda in each of those states.

Trump is focused on this trio for the same reason that liberal activists are: Donnelly, Manchin, and Heitkamp are the only Senate Democrats who refused to sign a pledge to oppose any tax plan that includes “cuts for the top one percent” back in August. All three are also up for reelection next year, in states Trump won by landslide margins in 2016.

One might assume then, that the choice before these senators is, ultimately: Should I put my own political self-interest above my partisan loyalty (and, perhaps, policy judgment)? Certainly, a lot of the coverage of the White House’s outreach to red-state Democrats has proceeded from that assumption.

And yet, it’s far from clear that Manchin, Donnelly, and Heitkamp would actually improve their reelection prospects by defecting from their party’s line.

To be sure, Donald Trump remains a popular figure in West Virginia, North Dakota, and, to a slightly lesser extent, Indiana. And eccentric Trumpist megadonors — along with corporate America’s various political arms — are certain to plow obscene sums of money into realizing Trump’s proposed bonanza. Further, while the actual substantive content of the president’s proposal is deeply unpopular, the idea of an economy-expanding, “middle tax cut” — designed by business genius Donald Trump — has real appeal in red America.

So, Manchin & Co. have some incentive to court Trump’s praise — and corporate donors’ cash —by reaching across the aisle on taxes. And, thus far, all three have declined to sharply criticize the Republican plan.

But these senators would do well to carefully weigh the potential, electoral benefits of cutting a deal with Trump against the accompanying costs.

Republican strategists fear nothing so much as their base’s apathy. In interview after interview, “GOP insiders” have stressed that congressional Republicans are better off passing bad, unpopular legislation than disappointing the conservative base by passing no major agenda items, at all. During the final Obamacare repeal push, multiple GOP senators all but admitted that this crass political calculation was their sole rationale for supporting a hastily written bill that they did not understand.

Midterms are decided in no small part by enthusiasm gaps. If red-state Democrats save the Republican Party from total legislative humiliation, they will be narrowing an enthusiasm chasm that all GOP challengers, including theirs, would otherwise struggle to cross.

And a failed tax-reform bill could also gift at least some vulnerable red-state Democrats with politically weak, ideologically extreme Republican rivals: The worse the GOP leadership performs, the more likely Steve Bannon–backed wing nuts are to win GOP primaries. In 2012, Joe Donnelly snuck into the Senate by defeating a tea party Republican who had knocked off longtime incumbent Richard Lugar. A similar development may help keep in the upper chamber next year. As Morning Consult reported in August:

[A]ttacks on Donnelly raise a familiar danger for Republicans, who want to avoid a repeat of 2012, when [Republican Senate nominee] Mourdock pushed the party far to the right before crippling his own candidacy during the general election with comments on abortion.

The rhetoric between two leading GOP candidates, Reps. Luke Messer and Todd Rokita, has already grown toxic, with each trying to paint the other as a Washington insider; some Republicans fear an ideological purity test between contenders could lead to a backlash beyond the May 18 primary next year.

“There’s this lane for a more pragmatic conservative or a moderate to fill,” said the former GOP operative. “If [Messer and Rokita] are going far to the right and beating each other up, that’s definitely what Donnelly wants.”

Keeping the Democratic faith would also, of course, endear Manchin, Heitkamp, and Donnelly to Team Blue’s base — while betraying the party on supply-side tax cuts would subject them to the dismay of the Democratic leadership, and the ire of progressive pressure groups like Indivisible and MoveOn.

And it really shouldn’t be all that difficult for red-state Democrats to sell the progressive position on tax cuts for the rich, given that it is also the consensus position among conservative Republicans on that subject. Earlier this year, Trump tried to bully Manchin into voting for a bill that was popular with his constituents in the abstract (West Virginians don’t like Obamacare), but deeply unpopular with them in reality (West Virginians don’t want to lose the affordable health insurance that they secured through Obamacare). Manchin opposed it. And, by the end of August, one poll found that the Democratic senator was more popular in West Virginia than Trump himself. Donnelly and Heitkamp similarly saw no discernible backlash to torpedoing the president’s first legislative priority.

If Republicans have the votes to pass their bill, it might be in a red-state Democrat’s narrow political interest to jump on the bandwagon. (Although, even then, if tax “reform” still includes provisions that hurt upper-middle-class homeowners when it comes up for a vote, it’s may be unwise for Democrats to claim ownership of it).

But if the choice is between letting tax reform join Obamacare repeal in purgatory — and getting to Susan Collins’s right for the sake of bailing out Trump’s presidency — there is no good political reason for a Democratic senator to do the latter. If Manchin, Heitkamp, or Donnelly vote for the Trump tax cuts in such a circumstance, they won’t be doing it for political expediency — but for the love of upward redistribution itself.