Republican Senate candidates in some marquee races say they would be happy to campaign with the GOP's new vice presidential candidate, Rep. Paul Ryan (R-Wis.)

But others are apparently resistant to the idea.

Sen. Scott Brown (R-Mass.) isn't commenting on whether he would campaign with GOP vice presidential candidate Rep. Paul Ryan (R-Wis.)

Democrats have attempted to attach Ryan and his plan to Republicans all over the country, labeling Ryan their "running mate" and hoping his controversial Medicare plan hurts downballot GOPers.

The Fix surveyed Senate candidates in some top races -- a few of which we highlighted Monday as states where Ryan's V.P. nomination and his proposal to turn Medicare into a voucher program could matter. A couple of candidates in blue-leaning states have balked at tying themselves to Ryan, while Sen. Dean Heller (R-Nev.), Rep. Denny Rehberg (R-Mont.), and Rep. Rick Berg (R-N.D.) said they would welcome Ryan to the trail.

Ryan is in Heller's home state today. The two won't appear together, but Heller's campaign said it would be happy to do so in the future.

"Dean Heller has events scheduled in Reno on Tuesday, but he considers Paul Ryan a friend and looks forward to campaigning with him," said Heller spokeswoman Chandler Smith.

Rehberg, who was one of few Republicans to vote against Ryan's budget and has benefited from ads that play up this fact, nonetheless would campaign with him.

"Absolutely, we hope the presidential and vice presidential nominees of both parties will campaign here in Montana," Rehberg spokesman Chris Bond said. "It will remind voters of the contrast between Denny — who is glad to discuss why, like most Montanans, he's supporting the Romney-Ryan ticket — versus Sen. Tester, who is desperately trying to hide the truth about his 95 percent support for President Obama's harmful, liberal agenda that Montanans overwhelmingly reject."

Berg is running next door in North Dakota, another conservative-leaning state that Mitt Romney and Ryan are likely to win.

Spokesman Chris Van Guilder echoed the Rehberg campaign: "We welcome both presidential tickets to come to North Dakota and support their choice for Senate."

In contrast, Sen. Scott Brown's (R-Mass.) campaign declined to comment. Brown has sought to create distance between himself and Ryan, pointing to his votes against the Ryan budget and a 2011 op-ed he wrote on why he doesn't support it.

"While we don't agree on everything, I certainly appreciate his efforts to bring budgetary issues to the forefront," Brown said Monday, according to the Springfield Republican.

The Fix has also reached out to Rep. Heather Wilson (R-N.M.), who is running in a blue-leaning state, and Rep. Connie Mack (R-Fla.), who is running in the most senior-heavy state in the country. Wilson has put some distance between herself and Ryan's budget, and Mack has labeled it "a joke" but said he would have voted for it.

We will update this post as we hear back.