This may be the weirdest special election yet

Tuesday night will bring the latest showdown between Democrats and President Trump over a special congressional election, and at this point the victor is anyone's guess. It's a familiar story in the wake of Trump's election, and one that will determine far more than just the newest member of Congress.

This time around, the players are Democrat Conor Lamb, a Marine reservist and prosecutor, who's running against Republican Rick Saccone, a longtime state legislator. The battle is centered in western Pennsylvania, a slice of of the state that went big for Trump in in 2016. It should be a gimme for the GOP. But Democrats are doing much better than they have any right to be. Though Trump won Murphy's district by double digits, Saccone is struggling against Lamb, a conservative Democrat, who's been riding a wave of voter dissatisfaction with Trump and a fired-up Democratic base to neck-and-neck polling ahead of Tuesday's voting.

His strong campaign is a bad omen for Republicans in November, when elections across the country give Americans everywhere a chance to vote. In short, if Democrats all over the country do as well as Lamb is doing in Western Pennsylvania, Republicans will likely end up on the defensive in places they never expected.

Here's the twist though: The district the national parties are duking it out over, Pennsylvania's 18th, will essentially cease to exist the moment after polls close. That's because Democrats won a redistricting battle in Pennsylvania in February. The state Supreme Court ruled all the House district map drawn by the Republicans in years past was unfairly gerrymandered in favor of the GOP. So the court redrew the map. And the 18th was split into several new districts.

The one Lamb — the Democratic rising star — will have to run in if he wants to stay in Congress is much more liberal than the 18th. And there's already a primary going on that will take place in May, just two months and two days after tomorrow's special election. So that means Lamb has to run his appeal to Republican voters in a Trump district general election and his appeal to Democratic voters in a swing district primary at basically the same time.

Will it work? VICE spent some days on the ground in Pennsylvania recently to explore what happens when Democrats get everything they want, all at once.

This segment originally aired March 9, 2017, on VICE News Tonight on HBO.