Even before the rise of Donald Trump, Senate Republicans were girding for possible losses.
They have 24 senators up for reelection. Democrats only have 10. And Democrats have already started tying Republican candidates to the party's controversial frontrunner.
Senator John McCain, R-Arizona, is not exactly a Trump fan. He's called his views "uniformed" and "dangerous." But that hasn't stopped his Democratic Senate challenger Rep. Ann Kirkpatrick from running ads to try to associate him with the presidential candidate.
Like the one that says: "No matter what Donald Trump says, John McCain will support him for President."
Senator Chuck Schumer, D-NY, warned today that the strategy will be replicated in dozens of races across the country.
"Donald Trump won't make America great again, but he will make Republicans the minority again," he said.
Unlike McCain, many Republicans have been reluctant to outright denounce Trump. They fear that weakening the likely nominee will lead Republican voters to stay home in November, hurting GOP candidates down the ballot.
But today the Democratic leader of the senate, Harry Reid said that silence could give his party fodder, too. If Trump is the party's nominee "you can't run away from it," he said.
And some of the other incumbents up for reelection -- including Senator Rob Portman, R-Ohio, and Senator Roy Blunt, R-Mo. -- may have to pay the price, Reid warned.
Republicans point out that they're the ones seeing record turnout in the primaries, while Democratic turnout is down. But Democrats insist that if Trump is the nominee, their base will flock to the polls in November to vote against him.