In 12 states, more than half of state legislative seats are guaranteed to one of the two major parties in the 2020 elections, according to Ballotpedia’s 10th Annual State Legislative Competitiveness Report.

When a candidate from only one of the two major parties runs for a state legislative seat, it is all but guaranteed to be won by that party. Nationally, roughly one-third of the 5,875 state legislative seats up for election this year will be won by one of the two major parties due to a lack of major party competition.

The 12 states where more than half of all state legislative elections feature only one major party candidate are:

The chart below shows the number of seats without major party competition in all even-year elections since 2010:

On the other hand, Michigan, Minnesota, New Hampshire feature the highest percentage of seats with major party competition, all over 90%. In Michigan, 109 of the 110 seats up have major party competition in the general election.

Nationally, Democrats and Republicans are contesting a nearly-equal number of seats this year, with a 35-seat difference between the two parties. This is the most parity in the number of seats contested by each of the two major parties since 2010.