I don’t believe in accidents when it comes to politicians and parties, particularly when it comes to choosing a city for a national convention. The Democrats’ selection of Milwaukee for their 2020 convention makes sense considering Hillary Clinton was their first presidential nominee to lose Wisconsin since 1984.

And, according to a new Inside Elections metric we’re calling “Baseline,” the Badger State is the most competitive state in the country.

The Baseline Republican performance in Wisconsin is 48.89 percent compared to a Baseline Democratic performance of 48.84 percent, giving the GOP an advantage of just 0.05 points. That slim margin is one of the factors that makes Wisconsin one of three initial presidential Toss-up states, along with Florida and North Carolina.

Inside Elections’ Baseline calculates statewide and House election results from the previous four cycles into a single average (more specifically, a trimmed mean) in an effort to find a standard performance for a generic partisan candidate.

Republicans have a narrow Baseline advantage over Democrats in North Carolina (50-49 percent) and a larger advantage in Florida (51-47 percent). But even with a 4-point GOP advantage, the most competitive races in the Sunshine State in 2018 were decided by less than half a point, and a close presidential contest is likely in 2020.

Also watch: Reactions to Senate GOP 2020 hype video — ‘I’m ready for the cycle’

Overall, the Democratic nominee should start the general election with a narrow advantage over President Donald Trump, according to our initial Electoral College ratings. But a lot depends on who that nominee will be. Competitive states in the Midwest could look fundamentally different if Trump faces California Sen. Kamala Harris instead of, say, former Vice President Joe Biden.

For example, Democrats have a significant advantage in Baseline performance in Pennsylvania (7 points) and Michigan (4 points), particularly after sweeping victories in last year’s midterms, but Trump narrowly carried both states in 2016. We have both rated as Tilt Democratic for now, but the president’s chances would likely be better against a senator from Oakland compared to a nominee from Scranton.

On the other hand, Nevada has a Baseline Republican advantage of more than 2 points, but we have the Silver State initially rated as Leans Democratic as the presidential trend has not been in the GOP’s favor.

Overall, according to the Inside Elections’ ratings, the Democratic nominee will start the general election with a solid advantage in 16 states and the District of Columbia for a total of 209 electoral votes. And Trump will start with the upper hand in 21 states for a total of 164 electoral votes.

Initially, we have the Democratic nominee favored in six competitive states that total 60 electoral votes: Michigan and Pennsylvania (Tilt Democratic); Maine, Nevada and New Hampshire (Lean Democratic); and Minnesota (Likely Democratic). Winning all six of those states would still leave the Democratic nominee one electoral vote short of victory.

Trump is initially favored in four competitive states that total 51 electoral votes, including Arizona (Tilts Republican); Iowa (Leans Republican); and Georgia and Ohio (Likely Republican). Sweeping those states would get him 215 of the 270 electoral votes needed to win.

Of course, it’s still early. When handicapping an election, it’s helpful to know who the nominees are. That’s why it’s difficult to project the 2020 race for president 20 months before the election. And that’s also why it’s possible we won’t change our presidential ratings for at least another 12 months.