In another sign Democrat Betsy Markey is threatening U.S. Rep. Marilyn Musgrave's re-election hopes, the Rothenberg Political Report relabeled its rating of the 4th Congressional District race on Tuesday to "toss-up/tilt Democratic."

Rothenberg had previously rated the race as a "pure toss-up."

Politicker's Pindell Report and the Cook Political Report still rate the race as a "toss-up"; CQ Politics says the race still "leans Republican."

The Rothenberg Political Report's Nathan Gonzales told PolitickerCO.com that the rating change was due to a number of factors, including that -- unlike the past couple elections -- no third-party candidate is running in the 4th District and that Musgrave has a history of close races.

Recent polling, Gonzales said, shows Musgrave has "had a tough time even reaching 50 percent -- and in this environment where Republicans are still on the defensive, it's an extremely tough position for her to be in.

"I think (Musgrave) just had difficulties," Gonzales said. "Despite some of the Republican rhetoric about her remaking herself and changing her image, I don't think we're seeing that play out in the polling numbers."

Also, Gonzales said Markey has "a much broader appeal" than 2006 Democratic nominee Angie Paccione.

"I think she fits the district much better than Angie Paccione did," Gonzales said.

Markey's campaign, not surprisingly, lauded the rating change.

"The more data and analyses we see about Marilyn Musgrave's performance, and given the uncertainty of our economic future, the clearer it becomes that the people of the 4th district are ready for a successful business leader-not another professional politician-in Congress," said Markey spokesman Ben Marter in a press release. "These numbers tell us that Betsy Markey's focus on the economy and energy issues is really resonating with voters in this district."

Musgrave's campaign did not immediately return a phone call and e-mail seeking comment late Thursday morning.