Right about now, Gov. Robert F. McDonnell was supposed to be in the thick of the race to succeed him, headlining fundraisers, leading rallies and starring in TV commercials for his fellow Republican, Attorney General Ken Cuccinelli II.

Yet as the country’s most-watched political contest rages in Virginia, McDonnell is an outcast.

Amid a gifts scandal that is the subject of state and federal investigations, McDonnell has gone to great lengths — traveling to Afghanistan to visit troops, touting his accomplishments on a seven-day, statewide tour — to show he remains engaged and in charge as governor.

But he cannot even pretend to have a role in the governor’s race, a marquee contest that less than a year ago looked like his chance to plop a cherry atop his substantial legacy. In addition to spoiling his résumé, McDonnell’s struggles — and his exile — are widely seen as a pall on this year’s entire GOP ticket. Fundraising has fallen off. Ethics reform is a common campaign promise on both sides. It will be hard for McDonnell to escape blame if his party suffers deep losses at the polls nine days from now.

In the meantime, Cuccinelli and most other Republicans want nothing to do with him.

Timeline: Star Scientific and Gov. McDonnell

McDonnell has been scratched from Cuccinelli events, replaced by out-of-state headliners who still fit the description of “GOP rising star.” Cuccinelli mentions the governor in just one TV ad, and it’s not to put his arm around him: “Cuccinelli personally launched the investigation into Bob McDonnell,” it says. Pressed on a radio show to say when he will campaign with Cuccinelli, McDonnell managed only this: “Well, uh, if and when I show up, you’ll know.”

Prevented from seeking back-to-back terms, Virginia governors normally try to win a symbolic “second term” by vigorously promoting their party’s candidate for the job. This time around, McDonnell and the GOP have concluded that the best thing he can do for Cuccinelli is keep his distance.

It’s a tremendous turnabout for a governor who just last year was in the mix for the vice-presidential pick and served as a regular Mitt Romney surrogate. Not only Cuccinelli but also the Democratic candidate for governor, Terry McAuliffe, were modeling their campaigns on his “Bob’s for Jobs” approach.

Now, instead of raising millions for Cuccinelli, McDonnell is seeking donations to his own legal defense fund. Speculation about his future, once centered on a run for president in 2016, has shifted to whether — or when — he will be indicted.

“I think the scandal is about the best definition of a game changer as you can get,” said Nathan L. Gonzales, deputy editor of the nonpartisan Rothenberg Political Report. “He was one of the most popular governors of an emerging swing state. I think the scandal immediately changed how people evaluated him and his prospects.”

For some Virginia Republicans, what has transpired represents more than a political downfall.

“It’s a personal tragedy,” said Earle C. Williams, a retired defense-contracting executive from Northern Virginia and McDonnell supporter who ran for governor as a Republican in 1993. “I think he had great promise, and it seems to me that that promise has gone away.

“I still think he’s an honorable man,” Williams added. “But I think he’s in a minority of two if he doesn’t think he exhibited terrible judgment.”

McDonnell, through his spokesman, declined to be interviewed for this article.

It’s too early to write McDonnell’s political obituary, caution political observers, who note comebacks made by other tarnished figures.

“I think Bill Clinton could be elected pope right now,” said one Richmond Republican insider.

Others believe that McDonnell is less of a campaign liability than insiders assume. With Cuccinelli behind in polls and fundraising, some say the campaign has nothing to lose by deploying McDonnell, whom voters view no more unfavorably than either candidate.

“Call Bob McDonnell and hold rallies, events, anything and everything and get BOTH of y’all out in front of voters,” D.J. Spiker, a contributor to the conservative blog Bearing Drift, wrote last week. “Do ads, do mailings, and tie yourself to Governor McDonnell. Fifteen days out, we need a game changer, and we have one sitting in elected office.”

The governor’s last appearance with Cuccinelli was April 1, the day after The Washington Post reported that the governor and first lady Maureen McDonnell had promoted a dietary supplement made by Star Scientific around the time Star chief executive Jonnie R. Williams Sr. picked up the $15,000 catering tab for one of their daughters’ wedding.

In the weeks and months afterward came revelations of a $15,000 Bergdorf Goodman shopping spree for the first lady, a $6,500 Rolex watch for the governor, a $10,000 engagement gift to another daughter and $120,000 in money that McDonnell has described as loans.

McDonnell has said he provided no state favors in exchange for Williams’s largesse, but he has apologized for embarrassing the commonwealth and has returned the gifts.

Cuccinelli had his own ties to Williams, which has made McDonnell’s problems particularly sticky for him. Cuccinelli received $18,000 in gifts from Williams at a time when the attorney general’s office was defending a tax case against Star and prosecuting the former Executive Mansion chef, who blew the whistle on McDonnell’s relationship with Williams. Cuccinelli initially failed to report a portion of those gifts, worth $4,500, as well as substantial stock holdings in Star. He called those reporting lapses.

Richmond Commonwealth’s Attorney Michael N. Herring (D) reviewed Cuccinelli’s disclosure forms and found no evidence that he had broken the law. But Cuccinelli’s links to Williams have given McAuliffe an opening to question his ethics. That has made it harder for Cuccinelli to attack McAuliffe, who has made a fortune in a string of controversial deals, on that front.

McDonnell’s fall has had a measurable financial effect on this year’s elections.

The governor had been a prolific fundraiser, raking in almost $8 million for his Opportunity Virginia PAC in its first three years. But his rainmaking abilities all but dried up as the scandal unfolded early this year. His political-action committee took in $278,000 in the first six months of 2013 but just $10,000 over the past three, according to the Virginia Public Access Project, a nonpartisan tracker of money in politics.

A governor’s PAC typically draws less money in his final year as he starts headlining events that directly benefit his party’s nominees for governor and the House of Delegates, also up for reelection in gubernatorial years.

But the drop-off for Opportunity Virginia has been unusually steep. In his last full year as governor, Timothy M. Kaine (D), now in the U.S. Senate, pulled in about $800,000 for his PAC. At the current rate, McDonnell’s PAC will hit just $300,000 for the year. Republicans say the scandal has hobbled down-ballot fundraising, too.

“I think he could have made a big difference both in the crowds they would draw at their events, plus the amount of money — the size of the checks from the contributors,” said retiring Del. Lacey E. Putney (I-Bedford), who caucused with Republicans.

Having McDonnell actively rooting for Cuccinelli also would have deterred some moderate Republicans from crossing party lines to support McAuliffe, said C. Daniel Clemente, a Tysons Corner real estate developer who has backed McDonnell and Cuccinelli. Out of respect for McDonnell, Clemente said, “they’d either be behind Cuccinelli or neutral.”

Any consequences for Cuccinelli’s campaign, of course, pale next to those for McDonnell personally. Even some who fault the governor for the scandal — and for handling it in a way that led to a steady drip of revelations — expressed pity.

“I don’t know how that man has slept the last two or three months,” Putney said in an interview after the annual Labor Day parade in the western city of Buena Vista. “Every other day, another shoe drops.”

The Star matter has grown quieter in recent weeks. Legal observers have said that if prosecutors seek charges, they would not do so this close to the election for fear of creating the appearance of political motivation. The effect has been to marginalize McDonnell all the more, even as his scandal has moved offstage.

“Now I feel like his problems aren’t even the most talked-about issue in the race,” said the Rothenberg report’s Gonzales. “It’s the shutdown, and Cuccinelli’s and McAuliffe’s own issues.”

The Star affair also pulled back the curtain on McDonnell’s personal finances, in disarray because of investments made with relatives in three rental properties, each between $800,000 and over $1 million, just before the housing market crashed. McDonnell used $70,000 from Williams for maintenance and mortgage payments.

“His investment strategy seemed to be premised on something you’d get at the Olive Garden at a real-estate seminar,” said Bob Holsworth, a veteran Richmond political analyst. Holsworth has found that hard to square that with the governor’s record as a prudent fiscal manager.

“This is a double life,” Holsworth said, comparing revelations about McDonnell’s financial blunders to the discovery, years after the fact, that Democrat Charles S. Robb, the “milk-drinking Marine,” had spent time as governor partying with young women.

“We’ve known politicians to have double lives,” Holsworth said. “It’s usually sexual. . . . This is very different.

McDonnell’s approval ratings sank to 49 percent last month from 64 percent in May, according to a Washington Post/Abt-SRBI poll. Even so, just 39 percent disapprove of his job performance.

“There’s an awful lot to be proud of,” said House Speaker William J. Howell (R-Stafford). “I do believe in the long term, when people reflect on his four-year term as governor, they’ll say, ‘Gosh, we got an awful lot done.’ ”

For now, at least, McDonnell’s scandal seems to overshadow his accomplishments, including surplus budgets and a landmark transportation deal.

“The problem is, he goes on WTOP and no one wants to talk about that stuff,” said Del. David B. Albo (R-Fairfax). “They want to talk about the gifts.”