Republican U.S. Senate candidate Todd Young speaks after receiving the endorsementof the U.S. Chamber in Indianapolis, Monday, Aug. 29, 2016. Indiana’s Senate campaign has gained national prominence as Republicans try to hold onto the open seat also being sought by former Democratic Sen. Evan Bayh. Caryl Auslander, Vice President, Indiana Chamber of Commerce is at the right. (AP Photo/Michael Conroy)
Republican U.S. Senate candidate Todd Young speaks after receiving the endorsementof the U.S. Chamber in Indianapolis, Monday, Aug. 29, 2016. Indiana’s Senate campaign has gained national prominence as Republicans try to hold onto the open seat also being sought by former Democratic Sen. Evan Bayh. Caryl Auslander, Vice President, Indiana Chamber of Commerce is at the right. (AP Photo/Michael Conroy) Credit: Michael Conroy

WASHINGTON — Democrats have a better-than-even chance of winning control of the U.S. Senate in November, thanks in part to a backlash against Donald Trump, but it won’t be as easy as they hoped.

Most Republican Senate candidates are running solid, well-financed campaigns focusing on local issues in their states and distancing themselves from Trump’s many missteps. Incumbents fended off challenges from the far right. And major Republican donors like the billionaire Koch brothers have been focusing their money on saving Senate seats after taking a pass on supporting Trump.

But there’s another force at play, as polls suggest a troubling trend for Democrats: In state after state, Republican senators are running ahead of Trump, who for his part has recovered a bit from the dismal polls he scored after the conventions. That means that some people who might be inclined to support Democratic nominee Hillary Clinton also are prepared to back a Republican for Senate, a phenomenon known as ticket-splitting.

Trump has closed the polling gap with Clinton a bit in recent days, with a new CNN/ORC poll showing the real-estate mogul with a two-point lead.

But with Clinton leading in most polls, particularly in key swing states, some Republican senators are starting to openly campaign on the need for a Republican Senate to serve as a check on her. John McCain in Arizona, Marco Rubio in Florida and Pat Toomey in Pennsylvania are among those trotting out that message, a throwback to the strategy Senate Republicans used successfully 20 years ago when Bob Dole was foundering in the polls against Bill Clinton.

McCain and Rubio, co-authors of the 2013 Senate immigration overhaul that included a path to citizenship for unauthorized immigrants, have nominally endorsed Trump’s candidacy while criticizing many of his statements. Both are out-polling Trump and lead in general-election match-ups against Reps. Ann Kirkpatrick and Patrick Murphy respectively.

Toomey, however, has been losing in most recent polls to Katie McGinty, even though he has been doing several points better than Trump. Unique among endangered Republicans, he has yet to say whether he will vote for Trump, although he has ruled out a vote for Clinton.

But Florida and Ohio are both places where Trump is close enough that he could lose while the Republican senators win. Ohio’s Rob Portman is running a particularly sharp campaign against former Gov. Ted Strickland, which has prompted Democrats to ease up on their spending plans in the traditional battleground state.

The Clinton campaign has also complicated Democratic candidates’ plans to tie all Republicans to Trump. Eager to woo disaffected Republicans, the campaign has been putting out a competing message that Trump is an outlier even among his party.

Even so, the overall map still looks good for Democrats. In Wisconsin, Sen. Ron Johnson has been losing for months to former Sen. Russ Feingold, sometimes by double digits. And in Illinois, Sen. Mark Kirk faces tough sledding in President Barack Obama’s home state against Rep. Tammy Duckworth, an Iraq war veteran.

Democrats’ star summer recruit, former Sen. Evan Bayh, also leads Rep. Todd Young in Indiana, where Bayh’s name and sizable campaign war chest are significant advantages. Even so, Duffy says Clinton remains unpopular in Indiana and Bayh’s votes for Obamacare and other Democratic initiatives before he retired in 2010 could hurt him. Bayh has also had to play defense on having made millions after leaving the Senate and questions about his residency.

States in the tossup category include New Hampshire, where another star Democratic recruit, Gov. Maggie Hassan, has been polling a point or two ahead of Sen. Kelly Ayotte, and Nevada, where Republican Rep. Joe Heck has either been tied or slightly ahead of former state Attorney General Catherine Cortez Masto.

A Heck win would make a Democratic takeover much more difficult and would be a bitter end for retiring Democratic leader Harry Reid’s career to boot.

Democrats also unexpectedly have a serious shot at wins in several Republican-dominated states, including Missouri, where Jason Kander is a handful of points down to Sen. Roy Blunt in the polls, and North Carolina, where Sen. Richard Burr has been clinging to a narrow lead over Deborah Ross.

One clear misfire for the Republicans this year is in Colorado, where polls show Democratic Sen. Michael Bennet blowing out Republican challenger Darryl Glenn by double digits after Glenn rode the backing of groups like the Senate Conservatives Fund and support from Sen. Ted Cruz of Texas to a surprising victory in the primary.