The Cook Political Report's National Editor Amy Walter said on Tuesday that President Trump Donald John TrumpSteele Dossier sub-source was subject of FBI counterintelligence probe Pelosi slams Trump executive order on pre-existing conditions: It 'isn't worth the paper it's signed on' Trump 'no longer angry' at Romney because of Supreme Court stance MORE poses a challenge for Republican midterm candidates because of their close association with him.

“The big challenge for Republicans is that they’re attached to him [Trump] in a way that we just have not seen of a presidential candidate,” Walter told Hill.TV's Krystal Ball and Buck Sexton on "Rising."

“I don’t remember ever seeing — in fact, I look at this — any Democrat in 2010 in a primary running as ‘I am the Obama candidate’ in the way you see Republicans running as 'I am the Trump candidate,' " she continued.

Trump has hit the campaign trail for various GOP candidates and told Sean Hannity during a radio interview on Friday that he intends to campaign “six or seven days a week” during the final two months of the campaign season.

While 87 percent of Republicans said they approved of the president, his overall approval rating sits at 43 percent, based on an average of polls, according to RealClearPolitics.

"That's a very, very dangerous place to be as a Republican, and it just seems really hard for me to see how they're able to hold the House if all of those seats truly play up to their expectations," Walter said.

— Julia Manchester