A safe VP pick, or boring?

But most important, say those who know him, he will never go rogue.

"It's important that his mate doesn't distract, and Portman won't do that," said Republican strategist Steve Schmidt, who came to regret his part in selecting then-Alaska Gov. Sarah Palin as John McCain's 2008 running mate.

Romney is said to be weighing candidates who also include former Minnesota Gov. Tim Pawlenty, Minnesota Rep. Paul D. Ryan, Louisiana Gov. Bobby Jindal, New Hampshire Sen. Kelly Ayotte and Florida Sen. Marco Rubio.

But the two names Romney watchers are tossing around most are Portman and Pawlenty, both mild-mannered Midwesterners who have often been characterized (unfairly, they would protest) as "boring." A Romney-Portman ticket, quipped comedian Stephen Colbert, would be "like the bland leading the bland."

The Cincinnati Enquirer recently investigated Portman's record and found nothing more scandalous than a 2007 traffic ticket for making an improper turn.

In London late last month, NBC anchor Brian Williams jokingly asked Romney to confirm reports that he was seeking an "incredibly boring white guy for your vice presidential nominee."

When it comes to Republican vice presidential candidates this year, boring is the new Palin.

Pawlenty, at least, has some name recognition. And his blue-collar roots might provide Romney some working-class ballast, compared with Portman, whose father launched a successful forklift company that was eventually sold to a Dutch company.

But Portman is unknown even to some Ohioans. The Columbus Dispatch recently asked 15 people in Genoa if they knew Portman. Only five had heard of him. And only two knew he was their junior U.S. senator.

Democrats, predictably, are faint in their praise. "You need a vice president, and the first rule is, do no harm," said former Ohio Democratic Party Chairman David Leland. "Obviously, Portman satisfies that rule, but other than that, I am not sure what he brings to the table for Gov. Romney."

Portman, 56, may not set folks' hair on fire, to use one of Romney's phrases, but unlike with Palin, few will wonder about Portman's one-heartbeat-away suitability for the job.

He's already mastered an essential tool of the modern presidential campaign, the pivoting segue.

Should Romney release more than two years of tax returns? "Americans are a lot more concerned about their own tax returns," he told The Times.

Have the attacks on Bain Capital hurt Romney? "If you look at what President Obama has done, he took our money, put it in the so-called stimulus plan and then outsourced a bunch of jobs," he said. "Our tax dollars were used to outsource jobs."

A former international trade lawyer with gray hair, icy blue eyes and an athlete's slender build, Portman once served on the board of the Nature Conservancy. He is an avid kayaker who comes to life when telling stories about his adventures on the water.

At the Ohio River Way Paddlefest this summer, according to the Associated Press, he said he popped a dislocated shoulder back into place on a South American river after recalling a scene from "Lethal Weapon." He used to practice rolling his kayak in the House pool with Colorado Sen. Mark Udall, a Democrat, and still teaches wounded veterans the skill in the pool at Walter Reed National Military Medical Center.

As a congressman, he served as the House's Republican conduit to the White House. During his 12 years in the House, he supported welfare reform, a ban on unfunded mandates, and the elimination of capital gains taxes on most home sales, and he co-sponsored a bill to swap Costa Rican debt for the preservation of tropical forests. He also spearheaded the creation in 2004 of the National Underground Railroad Freedom Center in Cincinnati.

Known for cordial relationships with Democrats, Portman somehow unchained his inner attack dog when he was recruited to play Democratic opponents in debate prep sessions in the last three presidential campaigns.

In 2000, he played Al Gore to George W. Bush and Joe Lieberman to Dick Cheney. In 2004, he played John Edwards in debate prep with Cheney, and in 2008, he played Barack Obama for John McCain. "He gets under your skin," McCain recently told the New York Times. "I hate him still."

"It's easier being mean as a Democrat," Portman explained recently at the opening of a Romney call center in this Cincinnati suburb. There, as he spoke to reporters, his hands trembled slightly. Someone close to him, who claimed to have seen his medical records recently, said the tremor was medically insignificant.