There are infinite what-ifs swirling around the results of last month's election, as is probably to be expected given the tight vote margin by which Donald Trump won his electoral college victory. What if FBI director James Comey hadn't sent that letter? What if Hillary Clinton had spent more time in Michigan? What if it hadn't been Clinton at all at the top of the ticket? What if, what if, what if?

That third question may bubble back to the top of the conversation this week, thanks to a new poll from NBC News and the Wall Street Journal. The pollsters asked Trump voters why they ended up backing his candidacy, offering a short list of options from which people could pick. The most common reason people cited as their most important for backing the Republican? To keep Clinton from getting to the White House.

(No, I don't know how the percentage of people calling an issue the "most important" totals over 100 percent across the six options -- but we'll come back to this.)

Clinton's deep-seated unpopularity didn't do her any good over the course of the campaign. Trump's didn't either for the first 99 percent of it, but it seems pretty clear that the alternative option was a big part of the reason that, in the end, many Republican-leaning voters came out to vote for Trump.

But let's set that aside for a second to instead consider some of the other choices the pollsters offered to those Trump voters. Like Trump's hard-line stance on immigration, which powered him to prominence in the primary but which apparently waned in importance for general election voters. (We could see this coming.) In exit polling, immigration was similarly viewed as less important than the economy as a motivator for their votes. Clinton won the half of the electorate focused more on the economy and Trump won the 13 percent who voted because of immigration.

Now let your eyes drift lower, to that bottom item on the list. Only a bit over a third of people who voted for the Republican candidate for president did so in part because it was fairly or very important to pursue traditional Republican policies. An equivalent percentage said that this wasn't really a reason for their Trump vote at all. That couples with the item a bit higher on the list: 81 percent of Trump voters indicated that a significant part of their vote was centered on changing business as usual in Washington.

The pollsters asked the question in a different way, too, asking which of the reasons above was the most important overall.

The winner was improving the economy. A fifth said to change Washington (a bit lower than those who said it was to keep Clinton from changing Washington). A robust 1 percent of respondents said that they wanted Republican Donald Trump to go to Washington and act like a normal Republican.

That's the quandary for folks like House Speaker Paul Ryan (R-Wis.) and Senate Majority Leader Mitch McConnell (R-Ky.). Their constituencies overlap with Trump's -- he won both Ryan's House district and McConnell's home state. But they won while running as members of the Republican establishment, and in Washington they lead caucuses made up largely of people in the same position. They're the D.C. that Trump voters want to change, offering the policies about which Trump voters are indifferent.

The irony, of course, is that Trump isn't heading to the White House with many detailed policy proposals of his own that can be juxtaposed with what the Ryan-McConnells have to offer. Trump voters want new policies and change and Trump is happy to oblige -- but that change exists as a nebulous idea, not as a detailed, countervailing platform. Trump's shown willingness to break old traditions, certainly, but we'll see what happens when that willingness conflicts with the core beliefs of the status quo.

The Post’s Matea Gold looks at how Donald Trump’s pledge to “drain the swamp” of special interests compares with his Cabinet picks so far. (Bastien Inzaurralde/The Washington Post)

Compared to where the Republican leaders expected to be two months ago, this is a wonderful problem to have, like your mom suddenly saying you can skip school for the day if you clean your room. Republican leaders are all happy to tidy conflicts up a bit if it means that they otherwise have full rein on Capitol Hill.

Because that's the other what if: What if Clinton had actually won? Trump voters may be indifferent about Ryan, McConnell and their policies -- but Ryan, McConnell and their policies were all empowered anyway. For most Trump voters, that was a better option than President Clinton.