Ken Cuccinelli has drawn financial and political support from different sectors of the GOP than did Gov. Robert McDonnell. (Steve Helber/AP)

Virginia Attorney General Ken Cuccinelli II has had his differences with Gov. Robert F. McDonnell — on transportation funding, on economic incentives for businesses and even on whether he should be running at all to succeed his fellow Republican.

But this week, Cuccinelli, the GOP gubernatorial nominee, distanced himself from McDonnell on the most pressing issue yet: the deepening ethics scandal surrounding a wealthy donor’s money and gifts to McDonnell, which Cuccinelli said is “very painful for Virginia.”

That statement from his campaign and their past differences underscore Cuccinelli’s delicate task: winning over McDonnell’s supporters as he pledges to be a very different governor.

While Democratic nominee Terry McAuliffe has portrayed himself as an heir to McDonnell’s pragmatic, business-friendly governing style, Cuccinelli has largely run for his job without embracing the legacy of the incumbent, even though they hail from the same party and McDonnell has enjoyed strong job-approval ratings.

The two Republicans have not been close, and Cuccinelli defied McDonnell’s wishes by running in the first place, pushing aside McDonnell’s preferred successor, Lt. Gov. Bill Bolling. Cuccinelli has drawn financial and political support from different sectors of the GOP than did McDonnell. And Cuccinelli has split from McDonnell on major policies, making clear that his governorship would not be McDonnell 2.0.

Timeline: Star Scientific and Gov. McDonnell

“When a candidate is running to succeed a popular incumbent of his own party, they generally tend to hug that incumbent pretty tightly,” said Dan Schnur, a former aide to California Gov. Pete Wilson (R) who runs the Unruh Institute of Politics at the University of Southern California.

Schnur cited the example of George H.W. Bush, who ran for the White House in 1988 essentially pledging to deliver Ronald Reagan’s third term. Al Gore, by contrast, campaigned in 2000 by distancing himself from Bill Clinton, a strategy some observers have called a mistake.

Although Cuccinelli is focusing his campaign message on jobs and economic growth, the way McDonnell did in 2009, Cuccinelli opposed McDonnell’s signature policy achievement — an overhaul of how the state pays for transportation projects — and rarely praises McDonnell’s achievements.

“Ken Cuccinelli is Ken Cuccinelli,” said Cuccinelli adviser Chris LaCivita. “He’s not Bob McDonnell, and he’s not Bob McDonnell lite. But what he has said publicly is that he wants to continue the focus of the administration, which has been jobs and the economy.”

What’s not clear is whether the differences will insulate Cuccinelli from a trait they share in common: a history of taking gifts from Jonnie R. Williams Sr., the wealthy donor who is chief executive of dietary supplement manufacturer Star Scientific Inc. and whose interactions with the McDonnell family are now under investigation.

Monday in Norfolk, Cuccinelli suggested that he was not concerned that the scandal would hurt his campaign.

“I’m not worried,” he said. “I mean, this isn’t related to me, so the case will take the course it should, and my main concern as attorney general is simply that the truth be brought out.”

By Wednesday evening, after The Washington Post reported on more than $100,000 in previously unknown checks given by Williams to the McDonnells, Cuccinelli’s tone had changed. “What we’ve all been seeing has been very painful for Virginia, and it’s been completely inconsistent with Virginia’s very reserved traditions,” he said in a statement.

Democrats say the Republican is too enmeshed in the Star Scientific story to plausibly distance himself from it.

“If Ken Cuccinelli’s history of receiving (and ‘forgetting’ to disclose) gifts from Star and Jonnie Williams is any indicator, his version of ‘reserved traditions’ is pretty far off from most Virginians,” the Virginia Democratic Party said in a statement.

McAuliffe embraced McDonnell on the transportation package, touting his support for the measure to demonstrate that he was willing to work across the aisle. Cuccinelli, by contrast, opposed it because of its tax increases and because he believes it concentrates too much authority at the state level.

Meeting with the Retail Alliance of Norfolk this week, Cuccinelli made clear that he would take a different approach to transportation decision-making.

“Gov. McDonnell took a pretty broad view of government reform across the whole state government. I’m going to take a very narrow and deep view,” Cuccinelli said, singling out the Commonwealth Transportation Board as an entity “just screaming to be streamlined.”

Cuccinelli also told the retail group that the Virginia Port Authority “did the right thing” in not privatizing the Port of Virginia, rejecting an idea McDonnell encouraged.

And while McDonnell has frequently used cash from the Governor’s Opportunity Fund to encourage businesses to move to Virginia or expand in the state, Cuccinelli has said he “won’t rely on it quite as much as it’s been relied on in the past. We’re going to reduce those things.”

When then-Lt. Gov. Timothy M. Kaine (D) ran to succeed Gov. Mark Warner (D) in 2005, Kaine made clear that he hoped to continue many of Warner’s policies, recalled pollster Peter Brodnitz, who worked for Kaine’s campaign. In 2009, McDonnell — while differing with the two Democrats on policy — suggested that he would have a similar, consensus-building governing style.

“It is unusual that Cuccinelli would say that even though these [last] three governors have a lot in common stylistically, [he is] different,” Brodnitz said.