[img_assist|nid=1234|title=U.S. Rep. Mark Udall|desc=Getty Images Photo|link=none|align=left|width=420|height=318]A new Rasmussen Reports poll of the Colorado U.S. Senate race shows Democrat Mark Udall with a 6-point lead over Republican Bob Schaffer -- the first time a Rasmussen poll has shown either candidate with a lead outside the margin of error.

The poll of 500 likely Colorado voters, taken on May 19, showed Udall leading Schaffer 47 percent to 41 percent. The margin of error was +/- 4.5 percentage points.

In April, Udall had a statistically insignificant 3-point lead; March's poll showed Schaffer up by a single percentage point.

In the past two months, Schaffer's overall ratings have dropped: his overall favorable rating in May of 44 percent is down 3 percentage points since April and 9 percentage points since March. His overall unfavorable rating, meanwhile, has increased 7 percentage points - from 32 percent in March to 39 percent in May.

Udall's overall favorable rating for May was 50 percent -- up two percentage points from April, but down two points from his March favorable rating. The Democrat had a May unfavorable rating of 35 percent, compared to 37 percent in April and 34 percent in March.

When asked for comment via e-mail, Schaffer manager Dick Wadhams responded, "Polls have gone up and down and will continue to do so."

But Matthew Miller, communications director for the Democratic Senatorial Campaign Committee, said the new poll numbers are "a clear sign that the repeated news about his involvement in the Jack Abramoff lobbying scandal is taking a toll on his candidacy."

However, the Rasmussen survey indicated the controversy surrounding Schaffer about the Northern Marianas Islands hasn't taken strong root among Colorado voters. Only 37 percent of those surveyed in the May poll said they were even somewhat concerned about Schaffer's alleged relationship with now-jailed former lobbyist Jack Abramoff.

Part of this may reflect a public expectation that politicians will be involved with lobbyists, Rasmussen Reports speculated: 70 percent of those surveyed said they believed most politicians would be influenced by a lobbyist.

Udall spokesperson Taylor West said in an e-mail that the new poll "is certainly evidence that Coloradans are responding to Mark Udall's strong record of standing up for Colorado and recognizing that Bob Schaffer would keep taking our country in the wrong direction." 

But, West added, "We expect this campaign to be close, and we'll be working hard to make sure Coloradans get to know Mark, his Colorado roots, and his commitment to doing right by Colorado families."