The last time Democrats controlled the government in Delaware County, a suburb of Philadelphia, the U.S. Civil War had just ended.

But on Tuesday, Democrats ended a century and a half of Republican dominance. In two other Philadelphia-area suburbs, they captured Chester County’s board of commissioners for the first time in history and seized control of Bucks County’s board of commissioners for the first time since the 1980s.

The Democratic gains in Pennsylvania, a state crucial to U.S. President Donald Trump’s election in 2016, suggest Republicans have yet to staunch the bleeding in the suburbs, where voters have increasingly revolted against Trump’s heated rhetoric.

The results should “scare” Republicans ahead of the November 2020 election, said Douglas Heye, a strategist who previously worked for the Republican National Committee.

“More and more data suggests we’re seeing a flight away from Republicans in suburban areas,” Heye said.

There were warning signs in other historically Republican strongholds as well.

In Kentucky, where Trump this week held a campaign rally to bolster Republican Governor Matt Bevin’s reelection bid, a Democratic challenger scored an upset win driven in part by a strong performance in suburbs of northern Kentucky outside Cincinnati, Ohio.

In Virginia, Democrats captured total control of state government for the first time in a generation, flipping both chambers of the legislature on the strength of wins in the rapidly growing and diversifying suburbs of northern Virginia and the capital of Richmond.