Democrats hold an advantage ahead of the midterm elections, but a Washington Post-ABC News poll shows that edge has narrowed since January.

That’s a signal to party leaders and strategists, the Post writes, that they could be premature in anticipating a big wave of victories in November. The poll finds the gap between support for Democratic vs. Republican House candidates has dropped by more than half since the beginning of the year. And at the same time, there has been a slight increase in President Donald Trump’s approval rating, though it remains low.