Many Democrats and liberals are fixated on one question regarding the 2020 primary: Who can beat Donald Trump? Dave Weigel reports that even some Democratic women are leaning towards Joe Biden because the 2016 election apparently proved a female candidate can't win. "[T]he likelihood of defeating Donald Trump is to me overwhelmingly the most important factor in choosing a candidate - factors one through three, really one through 300. The key is just figuring out who that person is," writes Josh Marshall.

But this is an impossible task, and therefore a bad thing to prioritize. Rather than trying to guess who might appeal to people who are not loyal Democrats, better to simply pick a candidate you actually like.

The election of Donald Trump ought to have put paid to the idea that anybody knows anything about who can win. The man was a reality TV show host, credibly accused of multiple instances of sexual assault, patently corrupt to his back teeth, and had no political experience whatsoever. Surely this guy can't win, right? For the whole campaign, political commentators were openly contemptuous of the idea that he could win either the primary or the general election. All the election data shops predicted that Clinton would win easily. But nope!

The political details of any country are far too complicated and uncertain to be able to predict with any kind of consistent confidence. You've got to consider whether a candidate will be able to organize an effective national campaign, how he or she will perform in speeches and debates, whether some hidden dirty laundry might come up, what might happen to the economy, whether there will be some disaster and how that might play, and about 50 other factors.

To be sure, sometimes it is possible, like the second round of the recent French presidential election where Emmanuel Macron had a consistent 30-point polling lead and went on to crush the far-right Marine Le Pen. But that kind of gigantic difference is fairly rare — in the first round of the French election, a swap of just 1 percentage point could have meant Macron facing Jean-Luc Mélenchon or François Fillon, which would have turned out very differently.

This holds doubly true for the United States, due to our unnecessarily complex constitutional structure. Victory in a presidential election depends not on overall votes, but who wins a tiny handful of swing states. Polls are usually pretty accurate across the whole country, but as we saw in 2016, they can be badly wrong in individual states.

Furthermore, any candidate might draw a third-party challenger that is strong enough to split the lefty vote and throw the election to Trump — and that's as true for centrists as it is for leftists. Howard Schultz has threatened to run a third party campaign if the party nominates Bernie Sanders, but the Green Party's Jill Stein won more votes than Hillary Clinton's margin of defeat in the key states of Michigan and Wisconsin, and the Libertarian Party's Gary Johnson did the same in those two states, plus Pennsylvania.

There's no sense in fussing too much about either Greens, libertarians, or greedy centrists refusing to vote tactically. In a democracy, people have choice, and the whole system depends on people voting out of a sense of moral duty. The most logical thing to do tactically speaking is not vote at all, since the chance of your vote swinging the election is virtually nil. In a parliamentary system, people could simply vote their conscience and assemble a coalition afterwards, but potential splitters is simply an unavoidable aspect of the crummy U.S. Constitution.

As Alex Pareene argues, "electability" is always invoked as a reason why the Democratic Party can't have nice things — why liberals must vote for the worse candidate, because the alternative is Republicans winning. It's left the party in a defensive crouch, terrified of its own shadow, convinced that America can't have anything but occasional bursts of penny-ante reforms.

I knew people personally who shared Bernie Sanders' politics but thought voting for him in the 2016 primary was too risky. And while one can't say for sure he would have been able to defeat Trump, he certainly couldn't have done any worse. Those voters may as well have gambled on someone whose record actually matched their values.

The reality is that we can't know who would be the strongest challenger to Trump. The only thing we can say is that Trump is consistently unpopular, especially given how strong the economy is, and he trails most Democrats in polls. Actual Republican policy, meanwhile, is even less popular than Trump. Almost nobody wants the tax cuts and deregulation the GOP is stuffing down the country's throat.

Trump has a dedicated base, but he is almost certainly beatable. Voter enthusiasm and dedicated support will surely help — as the GOP itself shows, a fanatically dedicated minority can punch far above their political weight. The best option for Democratic primary voters is to research the candidates' positions and records, and pick the one they think is best.

Being timid and going with the "safe" choice backfired horribly in 2016. It's time to go for broke.