The libertarian independent would easily pull the 80,000 Midwestern votes that made the difference in 2016.

When Rep. Justin Amash (I–Mich.) consciously decoupled from the Republican Party on the Fourth of July, he also left open the possibility that he might run for president in 2020 as either an independent or a Libertarian. If he chooses to do that, he will most definitely make it harder for either President Donald Trump or the eventual Democratic nominee to eke out a victory. Obviously, the next president will be either a Republican or a Democrat, but his presence will make them work much harder for victory.

As Amash's former policy adviser Kurt Couchman explains in a column at CNN's website, the congressman presents an alluring policy profile that would certainly draw from both of the major parties:

As a constitutionalist, consistent proponent of liberty, devoted family man, and faithful Christian, the now-former Republican could easily attract votes from otherwise reluctant Trump voters. And in competitive states like Pennsylvania, Wisconsin and, of course, Michigan, small margins make a big difference. Also, he would draw votes from Democrats. He opposes corporate welfare and other forms of corruption, he vocally backs civil liberties against both parties' leadership, he stands against global militarism, and he frequently engages bipartisan coalitions to advance reforms.

Recall that had Hillary Clinton pulled just 80,000 more votes in Michigan, Wisconsin, and Pennsylvania, she would have beaten Donald Trump. Amash might have limited name recognition right now, but he's definitely a known quantity in the Wolverine State and his appeal is going to be strongest in Midwestern states such as Wisconsin, Ohio, and Indiana (the western part of Pennsylvania is effectively part of that region too).

Yes, it's early, but none of the Democratic candidates has anything approaching the charisma and upside potential of Barack Obama and Donald Trump, despite hitting a "career-high approval," is still disliked by a majority of Americans. I think that Trump, absent a recession or a new scandal of immense proportions, is likely to win in 2020, but the race will be as razor-thin as the one against Clinton. Having the heartland-resident Amash in the mix could easily swing things one way or another.