Adding to your numbers is generally good in politics, especially in the U.S. Senate. To pass Republican legislation, you need every vote, as the Obamacare plight of the summer showed, and partisan control of the Senate hangs in the balance in the 2018 election.

But adding to your numbers isn’t an absolute good. It's a means to an end.

Bringing Roy Moore into the Senate Republican Conference is not worth the moral cost. The purely pragmatic calculation gripping many Republicans — that an extra Republican in the Senate is absolutely crucial — is based on the sort of hubris and moral blindness conservatives ought to eschew.

The preponderance of evidence suggests that Republican Alabama Senate candidate Roy Moore is guilty of sexual impropriety on multiple occasions. That was his reputation. That is the story told by multiple alleged victims and it's a pattern of behavior corroborated by many independent sources.

Some conservatives say they don’t care about his character. He’ll "vote right,” they say. He’s necessary to pass tax reform and may be necessary to keep the Senate majority and confirm conservative judges after next year’s election.

This line of reasoning is that we should suspend our moral judgment of the man for the sake of the things he can provide us.

The first problem is practical: We can’t even be sure he’ll deliver what we want. Moore is famously anti-establishment. He hates Majority Leader Mitch McConnell of Kentucky and had to beat President Trump’s endorsed pick in order to win the nomination. Now Sens. Ted Cruz of Texas and Mike Lee of Utah have turned against him. Will Moore really cast a conservative vote if it means giving a victory to McConnell, Trump, or Lee?

Do you really want to count on the moral compass and the word of a man whose moral compass is so dubious?

The second problem is that we can’t be totally sure we’ll need him. Tax reform could pass without him, or it could fail by a handful of votes and he won’t make a difference. Republicans could either keep the Senate majority in 2018, or fall to 48 seats, with or without Moore.

Acknowledging these uncertainties and our inability to predict the future is important. Our own unavoidable ignorance undercuts the argument that pragmatic considerations can trump principle. Pragmatic considerations that require predicting a future this hazy aren’t worth very much. And thus, it's impossible to argue that principle shouldn't rule the day.

If you’re stuck on pragmatism, though, or if you don’t subscribe to the archaic principle of not elevating sexual deviants to positions of power, then think of the long-term costs that seem more predictable than any short-term gains.

Imagine a well-intentioned honest liberal Democrat granted the power of clairvoyance in 1998. If he could look ahead to 2017, and see the consequences, what do you think he would tell his party about former President Bill Clinton? What would he say as the party leaders lined up feminist Gloria Steinem to write an op-ed defending Clinton, despite the affair with an intern half his age and the flood of charges of sexual assault or harassment? Maybe he would say, “Guys, let’s not establish the principle that character doesn’t matter in public office. Let’s not mock those objecting to sexual impropriety as mere prudes. Let’s not rush to ‘move on’ from President Clinton's crimes. If we do, we will suffer later.”

It’s not a stretch to suggest that the Left’s fierce, ruthless, and successful defense of Bill Clinton — and the virulent attacks on his critics and victims — paved the way for Trump's presidency.

Just so, there will be long-term consequences to any conservative embrace of that same nihilistic worldview that gripped the 1990s Democrats. And for conservatives, the consequences will be even worse, because conservatism as a philosophy requires boundaries, norms, and traditions that such a worldview cannot sustain.

In short, the cost of embracing Roy Moore is greater than the cost of possibly losing this Senate seat. Let the Left behave as if political ends justify any means. They will suffer for it in the long run. Let us choose to have dignity — even if the reward will be long in coming.