Still, Romney's team trusted Portman to talk to the reporters who traveled with Romney. A Portman aide snapped BlackBerry photos as the senator did a background briefing.
Less visible was Wisconsin Rep. Paul Ryan, whose role was limited to introducing Republican National Committee Chairman Reince Priebus at an event at a factory in Ryan's hometown of Janesville. Wisconsin Gov. Scott Walker, whose June 5 recall election victory was a big win for Republicans, introduced Romney and accompanied him on a tour through the factory.
Romney's Boston headquarters has been engaged for weeks in the secretive process of weighing the pros and cons of each potential pick.
With less than three months to go until Republican National Convention in August, the campaign has little time to waste as it meticulously prepares Romney to make one of his most important decisions. Advisers concede that Romney could make his pick earlier than right before the convention to help boost fundraising efforts.
Knowledge of the process has been limited to a few of Romney's highest-level aides. Information is on a "need-to-know" basis — and as far as those aides are concerned, there are few people inside the Boston headquarters who need to know, let alone reporters and other outsiders.
The process is so secret because it's so sensitive. A vice presidential vetting is possibly the most intense background check in politics. Everything is fair game: voting records and the political past, to be sure, but also personal issues.
"I think everyone should take a deep breath," Rubio said Tuesday. "Here's the one thing everyone should know: Gov. Romney's going to make a great choice. In that I'm confident."
Peoples reported from Washington.
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