WASHINGTON — When President Bush came to Tennessee last month to raise money for a Republican Senate candidate, Bob Corker, the event was a no-press-allowed affair held at a private residence.

When first lady Laura Bush came for the same purpose last week, she appeared at the Knoxville Convention Center, with Mr. Corker standing proudly at her side — and journalists most definitely welcome.

In this autumn of Republican discontent, party candidates who shy away from appearances with the president and Vice President Cheney are gladly greeting the barnstorming first lady.

“She is more popular, and more welcome, in many parts of the country than the president,” a White House press secretary during the Clinton administration, Ari Fleischer, said. “In races where the moderates are in the most trouble, Laura Bush is the one who can do the most good.”

The first lady’s press secretary, Susan Whitson, said Mrs. Bush has attended three or four times as many events this year as she did four years ago. She has helped raise more than $14 million, including the $500,000 she generated for Mr. Corker and the Tennessee Republican Party in Knoxville.

“She likes doing it, and, more importantly, she understands the importance of doing it,” Ms. Whitson said. “She’s happy to help any way she can.”

As she hits the campaign trail on behalf of Republican candidates, the first lady, 59, favors the velvet glove approach over hard-edged partisanship.

In Knoxville, she praised Mr. Corker’s position on education — her signature issue — and said he would work to keep taxes low and support the military.

“Bob’s dedication to the people of Tennessee, and his achievements, remind us of why he must be elected to the United States Senate,” she said.

Typically, there was no mention of Mr. Corker’s Democratic opponent, Rep. Harold Ford, or the national Democrats who have made antipathy to her husband an issue in the midterm elections.

While such positive, nonpartisan rhetoric is in keeping with the first lady’s image as a traditional political spouse removed from policy-making, “State of Denial,” a new book by a Washington Post assistant managing editor, Bob Woodward, paints a somewhat different picture.

Mr. Woodward writes that Mrs. Bush met frequently with a former White House chief of staff, Andrew Card, and supported his unsuccessful attempt to oust Defense Secretary Rumsfeld as part of a second-term housecleaning.

The White House press secretary, Tony Snow, on September 29 quoted Ms. Whitson as saying that Mr. Woodward’s account was “flatly not true.”

In a March 24 interview on CNN’s “Larry King Live” show, Mrs. Bush said she does discuss personnel matters with her husband. “That’s one of the things we do talk about the most, are personalities,” she said. “And I know everyone, as well as he does, who works here. I’ve worked with them also. So I would certainly give him that kind of advice.”

Mrs. Bush’s campaign stop in Tennessee was an example of the White House’s strategy to use her in competitive races. Mr. Corker is in a tough battle for the seat now held by the retiring Senate majority leader, Bill Frist. Recent polls show Mr. Corker in a virtual dead heat with Mr. Ford.

While the president carried Tennessee in both 2000 and 2004, he is currently no more popular there than in the rest of the nation. A poll by Middle Tennessee State University conducted September 19–30 found that Mr. Bush’s job approval was 40%, close to his rating in national surveys.

Earlier this month, the first lady starred at fund-raising events for a pair of embattled New York congressman, Thomas Reynolds and John Sweeney.

She also has campaigned for a trio of Connecticut House members — Christopher Shays, Nancy Johnson, and Rob Simmons — as well as Senator Chafee, a Republican of Rhode Island. All face difficult races.

While the president has occasionally campaigned in places where he’s especially unpopular, such as Connecticut, many candidates — among them Mr. Corker and Senator DeWine of Ohio — have appeared with him only at private events.Mr. DeWine is battling a stiff challenge from Democrat Sherrod Brown.

According to the president’s schedule and a list of public speeches, including fund-raisers, posted on the White House Web site, 46% of his campaign events during this election cycle have been private affairs off-limits to the press.

His wife, with no political baggage to speak of, has no qualms about venturing into campaign no-man’s land. “There aren’t many places where it is easy for the president to go these days, but that’s not true for her, and candidates don’t have to be afraid of being seen with her,” said Stuart Rothenberg, editor of the Rothenberg Political Report, a nonpartisan newsletter based in Washington.

While pollsters don’t often ask respondents to rate first ladies, a January USA Today/CNN/Gallup survey measured Mrs. Bush’s job approval rating at 82%. For the president’s second term, the first lady’s approval numbers have been roughly twice her husband’s.

They also compare favorably with other recent first ladies. Gallup surveys show Hillary Rodham Clinton left the White House with a 66% approval rating, Barbara Bush was at 85% early in her husband’s term, and Nancy Reagan left with 74% approving of her performance.