BEVERLY HILLS, Calif. — House Speaker Paul Ryan says a Democratic takeover of the House or Senate in November would lead to a stalemate in Congress and open the way for partisan investigations of the Trump White House.

He says Democratic control of either chamber would mean "subpoenas" and "the system shutting down."

Democrats have criticized the GOP-led House intelligence committee, which found no evidence that Donald Trump's campaign colluded with Russia in the 2016 presidential race.

Democrats need to gain at least 23 seats to retake the House. Republicans hold a 51-49 Senate edge.

Ryan said in California that a president's party typically loses seats in midterm elections, but that data shows the GOP would hold the House if the election were now.

But he's acknowledging "a great amount of enthusiasm" among Democrats.