U.S. Sen. Debbie Stabenow has a double-digit lead over Republican opponent John James in her re-election bid, according to a new poll released Monday.

Stabenow, D-Lansing, was favored by 55.5 percent of 600 surveyed likely Michigan voters 33 percent for James, a Farmington Hills businessman and combat veteran, with 10 percent undecided. Third-party candidates received 2 percent support.

The Sept. 5-7 poll, conducted for The Detroit News and WDIV-TV by the Glengariff Group, has a margin of error of plus-minus 4 percentage points.

Almost all of the poll respondents had heard of the incumbent, and 54 percent held a favorable view of her compared with 31 percent unfavorable. James' name ID was at 54 percent with 21 percent favorable to 15.5 percent unfavorable.

James faces an uphill battle against Stabenow, who is well-liked and known to voters, said Richard Czuba, the pollster for Glengariff.

"He has room to grow, but he is facing the same dynamics as every other Republican on the ticket, coupled with the fact that Debbie Stabenow is widely liked," Czuba said. "I just think the U.S. Senate race is shaping up to be a very hard climb for Republicans. Something significant would have to happen either with the nation or these candidates."

Stabenow's polling numbers "are moving into what I call Carl Levin territory. He would just systematically blow everybody out that Republicans put up against him, including Bill Schuette. She’s got very deep roots out-state, particularly among the agricultural community, and I think that’s reflected in these numbers."

When a candidate polls above 50 percent, he said, "that means voters know you and they’re with you. Republicans have got to then actually peel people back" who already say they support Stabenow.

“Whether it's protecting our Great Lakes, lowering the cost of health care and prescription drugs, or standing up for our veterans, Sen. Stabenow is focused on doing her job and what's best for Michigan," said Stabenow campaign spokeswoman Miranda Margowsky.

The poll numbers don't show a closer race, especially because James hasn't been up on television with commercials yet after the primary election, said campaign manager Tori Sachs.

"When voters hear that John James is a combat veteran and a job creator who is taking on a 43-year career politician Debbie Stabenow who has been paid nearly $4 million in taxpayer salary and only passed 5 bills into law, they overwhelmingly support John James," Sachs said.

Stabenow had $6.27 million in cash on hand as of July 18 compared with James' nearly $869,000. Stabenow has spent another $3.2 million to reserve television air time for the last four weeks before Election Day, and she's already been up in Detroit markets with ads touting her work in the Senate.

lfleming@detroitnews.com

(313) 222-2620

Twitter:@leonardnfleming

Staff writer Jonathan Oosting contributed.

Senate race

Debbie Stabenow 55.5%

John James 32.6%

Third party candidate 2%

Undecided 10%

Note: Numbers may not total 100 percent because of rounding. Poll of 600 likely Michigan voters had margin of error of plus-minus 4 percentage points.

Source: Glengariff Group