The threat of impeachment looms increasingly large over midterm season, setting up a battle between Democrats looking to downplay it and Republicans hoping to prove its legitimacy.

For the GOP, any evidence suggesting House Democrats would move to impeach the president, should they succeed at regaining power, is an electoral gift — raising the stakes, and giving candidates the juice they need to close that nagging enthusiasm gap. Some Democrats seem to understand that danger. “I don’t think we should be talking about impeachment. I’ve been very clear right from the start,” House Minority Leader Nancy Pelosi, D-Calif., said in April. “On the political side I think it’s a gift to the Republicans.”