Democratic U.S. Sen. Amy Klobuchar has widened her lead over Republican challenger Kurt Bills, who one week before Election Day remains unknown to a majority of Minnesotans, according to a new Star Tribune Minnesota Poll.

The poll shows that Klobuchar is backed by 65 percent of Minnesotans while Bills draws support from 22 percent, giving Klobuchar her widest lead yet.

The first-term senator's support stretches across the state and in nearly every demographic group. She has support from nearly all Democrats, 66 percent of independents and even 37 percent of Republicans. Bills captures less than half of Republican voters -- 47 percent.

"She's pretty personable," said Jim Mulville, 64, of Norwood Young America. Mulville calls himself an independent conservative and acknowledges that his libertarian views probably line up best with Bills. Nevertheless, he said he will vote for Klobuchar because her television ads show "she is more than willing to get in and help people with their problems."

Mulville, like most poll respondents, said he knows little about Bills. According to the poll, 52 percent did not recognize Bills' name, while 29 percent recognized the name but had no opinion of him. The rest held split opinions.

By contrast, Klobuchar, who has run more than $1.3 million of ads, has nearly universal name recognition, with 58 percent saying they viewed her favorably. Another 12 percent said they had an unfavorable opinion of her.

The result has been a race so dominated by Klobuchar that even those who do not support her acknowledge her strengths.

"I would probably go ahead and vote Republican," said Janet McCoy, 74, of Winona, Minn. "Although I kind of like Amy Klobuchar and some of the things she is doing in the state."

The poll was conducted among 800 likely Minnesota voters who were contacted on their landline or cellphones Oct. 23-25. It has a margin of sampling error of plus or minus 3.5 percentage points.

Klobuchar's campaign manager, Justin Buoen, said her strong numbers reflect her work.

"This poll shows that the senator works incredibly hard for the people of Minnesota and she does everything she can to put the people of our state first," Buoen said. "She works to find common ground with people of both parties."

Bills campaign manager Mike Osskopp acknowledged their campaign's deficit.

"Despite our best efforts, I don't think that we have been able to communicate our message as well as we would have liked to the people of Minnesota regarding Amy Klobuchar's woeful record," Osskopp said. He said he was still hopeful that Minnesotans looking for a change will vote for Bills next Tuesday.

Breaking down the results

Klobuchar, former Henn-epin County attorney, draws her heaviest support from the Twin Cities and surrounding suburbs. She draws 72 percent of voters in Minneapolis/St. Paul and 56 percent of suburban voters. Bills draws 17 percent in the Twin Cities. His strongest showing comes in metro suburbs, where 27 percent of voters say they will cast ballots for the Rosemount high school teacher. About 15 percent of suburban voters are still undecided.

The Minnesota Poll found that more Minnesotans identify themselves as Republicans than they did last month. In the September Minnesota Poll, 13 percent more Minnesotans said they were Democrats than Republican -- 41 percent self-identified as DFL, 28 percent GOP and the rest independent or other.

This month, there is only a 5 percentage point gap between the two major parties -- 38 percent identified themselves as Democrat, 33 percent Republican and 29 percent independent or other.

The new poll found a tightened presidential race, with President Obama's lead over Mitt Romney narrowed to 3 percentage points. But that has not translated into heightened support for Bills.

According to the poll, 47 percent of Romney voters said they would vote for Bills, while 37 percent said they would vote for Klobuchar. The Democratic senator also picks up support from 66 percent of the sliver of voters who said they are undecided in the presidential race. Nearly all Obama voters said they would vote for Klobuchar.

That includes Democrat Virginia Robertson of Fergus Falls.

"I think she's shown courage. I think she's shown leadership," said Robertson, 80. "I think she is well respected on both side of the aisle."

Christopher Cole, a Republican from Bloomington, said he is voting for Bills. But he believes Klobuchar will be re-elected.

"I prefer someone who is far more fiscally conservative," said Cole, 39. However, he said, "I don't think he's got the wide appeal that Amy does. It pains me to say that."

Rachel E. Stassen-Berger Twitter: @rachelsb