Justin Amash could have a big impact on the 2020 presidential race. But how?

Rep. Justin Amash’s decision to form an exploratory committee for a run for president as the Libertarian Party candidate could wind up being a very significant moment in the 2020 race.

Exactly why and how, though, isn’t entirely clear.

Amash (I-Mich.) has been toying with a third-party run since a well-documented rift between him and the Republican Party, which he left symbolically on July 4. Amash was a founding member of the tea party-oriented House Freedom Caucus, but his politics have always skewed more libertarian, and he said he became frustrated with the GOP over time. He went on to support the impeachment of President Trump, even as all of his former party mates in the House voted against it.

The case for him being a significant presence in the 2020 race is readily apparent. He’s not just a sitting congressman and former Republican, but he also hails from one of the most important states in the 2020 election: Michigan. The state went for Trump by just 0.2 percentage points in 2016 — the thinnest margin of any state. That means even a modestly strong showing by a Libertarian nominee could theoretically swing the state and potentially the race for presidency.

Exactly to whose benefit could that accrue, though?

Being a former Republican with conservative fiscal policies would seem to potentially attract GOP-leaning voters who are disillusioned with Trump but perhaps unwilling to move over to the presumptive Democratic nominee, former vice president Joe Biden. Amash also represents one of 14 Michigan congressional districts — and a conservative-leaning one at that, with the district going for Trump in 2016 by 10 points. A relatively strong showing (by third-party standards) in his home area could help him gain significant votes statewide. Libertarian nominee Gary Johnson, himself a former Republican governor, took 3.6 percent in the state in 2016.