With just a few short days until the election, it's decision time for undecided voters. Hillary Clinton's latest email scandal has stolen headlines this week, but there's another issue many wavering voters might be taking into consideration: where the candidates stand on abortion.

In one corner sits Clinton, a candidate who is abominable to pro-lifers. She is not just "pro-choice." She believes, like the extreme pro-choice special interest groups who support her, in abortion, subsidized by the taxpayer, as a constitutional right. She promises to appoint judges who will not only expand abortion to the farthest degree imaginable, but withdraw it from the democratic process, where the Constitution says it belongs, and possibly entrench it for a generation. This is far, far worse than "deplorable." It is an abomination.

But in the opposite corner is a candidate whose very person is a mockery of everything in which pro-lifers believe. Although Donald Trump has promised to appoint originalist judges who would overturn Roe v. Wade, this is as credible as every Trump promise, which is to say, not credible at all. His promises are undermined by his decades of pro-choice advocacy, his public defense of Planned Parenthood, and his decades-long dedication to libertinism.

In his own anti-Trump address to pro-lifers, Ross Douthat accurately describes a vote for Trump as:

...a vote for a man who stands well outside the norms of American presidential politics, who has displayed a naked contempt for republican institutions and constitutional constraints, who deliberately injects noxious conspiracy theories into political conversation, who has tiptoed closer to the incitement of political violence than any major politician in my lifetime, whose admiration for authoritarian rulers is longstanding, who has endorsed war crimes and indulged racists and so on down a list that would exhaust this column's word count if I continued to compile it.

It is a vote, in other words, for a far more chaotic and unstable form of political leadership (on the global stage as well as on the domestic) than we have heretofore experienced. [The New York Times]

While voting Trump is not a form of political violence, it is still a leap well beyond the norms of American politics, norms within which pro-lifers have heretofore been proud to play.

Morally, pro-lifers should withhold their vote from Trump for the same reason everyone else should withhold their vote from Trump: He is unqualified for the office he seeks. Period. End of story. (Yes, Hillary Clinton is also unqualified. They shouldn't vote for her, either.)

I recognize this moral argument is one not all pro-lifers will accept. Here, I want to make a much more brass-tacks, concrete, political argument: If pro-lifers vote for Trump, the Republican Party will never again give them what they want.

Let's face it: The Republican Party started screwing over pro-lifers long before it nominated the orange demigod of bro-choice. Before the death of Antonin Scalia, the Supreme Court had five justices appointed by Republicans, not four. And yet, Roe v. Wade stood. On issue after issue, in battle after battle, the institutional GOP has talked a good game, but folded when it mattered deeply to pro-lifers.

And their reasoning for doing so boils down to a very simple political calculus: Pro-lifers have nowhere else to go, so why should the GOP go to bat for them? But in terms of numbers, the GOP depends on pro-lifers. If pro-lifers stay home on election day, the GOP is toast. Except that pro-lifers aren't going to stay home, because they're too afraid of what the Democrats will do. The pro-lifers need the GOP more than the GOP needs them.

Politics is about power. It is about brinkmanship. For pro-lifers to succeed politically, they need to scare the Republican Party. And for the Republican Party to be scared, it must be threatened, and threatened credibly. If we still turn out for a candidate who is an open mockery of everything we stand for simply because we're scared, it is the end of the pro-life movement as we know it.

I know what you're thinking. "Yes but if Hillary gets in she will..." Maybe. Maybe not. But if pro-lifers don't declare their independence from the GOP, if pro-lifers instead demonstrate that they'll do literally anything for the GOP with nothing in return, simply because of a promise not worth the paper it's printed on, the pro-life movement is over, at least as a force in partisan politics. Period. Dead. It will be an ex-movement. Kiss it goodbye.

But if pro-lifers stay home and show the GOP that, yes, actually, it does need them to win elections, then we're talking. We're talking about a movement whose influence will finally start matching its numbers and the righteousness of its cause. We're talking about a movement that has a future, possibly even a bright one.