Where's former Gov. Mark R. Warner leaning as he ponders whether he will run again for his old job or for a U.S. Senate seat next year?

From his comments to business school students Friday and to reporters later, you could make a case either way.

His lecture to the students was heavy on federal policy issues: energy policy and its link to global warming; illegal immigration; international economics.

But then, he also spoke briefly but wistfully of his four years in Richmond and called his term as governor "the greatest job I ever had."

While sources close to the Democrat say he's leaning toward a 2008 race for the seat Republican U.S. Sen. John W. Warner will relinquish with his retirement, the telecommunications multimillionaire and venture capitalist made his fondness for executive positions clear.

"I loved being in business, but I loved being governor more," he said.

Warner left office in January 2006 with job-approval ratings in the mid-70s and briefly pursued a presidential bid that he abruptly abandoned in October. But within a week, he said, he would again be a candidate for either governor or the Senate.

Two Republicans immediately voiced interest in succeeding John Warner. Former Gov. Jim Gilmore said he is interested in the race and would make his decision after November's state legislative elections. A close aide to U.S. Rep. Thomas M. Davis said Davis will run, though Davis has not yet announced his plans.

Though Mark Warner and the 80-year-old senator are not related, they are friends. Even after Warner dropped his presidential plans, he traveled widely speaking largely about the U.S. role in finding energy alternatives to petroleum. He ruled out a second race against John Warner, whom he unsuccessfully challenged in 1996 in a campaign remembered for bumper stickers that read, "Mark Not John."

"In 1996, I was the new guy on the scene. Outside of my business friends, a lot of folks didn't know me. Now I've got a record in public life that they can judge and they've got an approach that I brought, and I'd be anxious to try to make that case," he told reporters.

Many Democrats are urging Warner to use his still-strong popularity in 2009. By electing another Democratic governor, the party could guard against catastrophic legislative and congressional losses when district lines are redrawn in 2011 if the GOP still controls the Virginia House and Senate.

Those who want him to run next year stress the importance of retaining or expanding the Democrats' one-seat U.S. Senate majority, won only last year after 12 years in the minority.

"If I'm not a candidate for Senate, there will be a very strong Democratic candidate. I've got a couple of folks who've talked to me already in terms of interest," he said.