How to handle the impending GOP nomination of Donald Trump, which would take an enormous step toward becoming reality if he wins Indiana's primary tonight, remains a source of much angst in the conservative movement. At the heart of the debate is whether an actual conservative should make an independent run against Trump and Democrat Hillary Clinton.

This debate hinges on a few factors. Some of these are highly implausible -- e.g., that a third candidate, despite being on relatively few state ballots, could win enough states to keep either Trump or Clinton from winning 270 electoral votes and thus throw the election to the House of Representatives, where the Republican majority would turn on their party's actual nominee and put this conservative third candidate in the White House. Free advice: Don't bet the 401(k) on that one.

Others are more worthy of consideration. At the top of that list is this question: Would a third candidate (for these purposes, we're excluding other parties such as the Libertarians and Greens) make it harder or easier for Republicans to hold onto their majorities in the House and, less likely, the Senate?

It's crystal clear that Democrats think Trump's nomination will help them not only keep the White House, but wrest control of Congress back from Republicans. For a preview of this fall's anti-Trump offensive, watch this:

So there's a real debate about how to prevent anti-Trump sentiment from bleeding down-ballot. The pro-third candidate argument goes like this: Lots of Republican voters, faced with a choice between Trump and Clinton, will simply choose to stay at home, costing the GOP's congressional candidates. A third candidate would give these voters more motivation to show up and cast their ballots, perhaps saving the party's congressional majorities.

I understand that argument, but I disagree with it. That's because I think a third candidacy would actually make life harder on congressional candidates because they'll be forced to take a side. Imagine Georgia's Johnny Isakson, campaigning for re-election this fall, being asked if he supports Trump (his party's nominee) or whoever was drafted to run as the third candidate. Without a third candidate, he can justifiably say something like, "I support my party's nominee, but he can speak for himself. I have my own race to run." With a third candidate, he can't do that. He'll be hounded into picking one, and by picking one he'll alienate those who back the other. It's a lose-lose proposition.

Turnout will be an issue either way (that goes for Democrats, too). Without a third presidential candidate, at least those Republicans running for Congress will be able to tell Republican and independent voters they should come out and support them as a hedge against either Trump or Clinton. I'm more sympathetic to the argument that a third candidate could articulate an actual conservative message, lest voters believe Trump really represents the political philosophy he's largely rejected. But I think most of that kind of clean-up will have to be done after the election.

It's not a matter of liking or supporting or even accepting Trump -- as is the contention of critics of a Wall Street Journal editorial today , which argued against a third candidacy for reasons similar to mine. I don't think any of my readers could mistake me for a Trump supporter. But I do think a GOP-led Congress is the best insurance against whatever bad ideas Trump or Clinton might pursue, and a third candidacy would just create another set of problems for the candidates seeking to maintain those majorities.