(CBS News) When Mitt Romney launches his four-day bus tour through four swing states this weekend, any number of things could go wrong.
Raucus, pro-Obama hecklers could unpredictably confront the candidate on the trail, fumble his attempts at friendly banter, drawing jeers from what should be an amiable crowd. Or, as Newt Gingrich knows all too well, the campaign bus could get a flat tire in a decidedly inopportune location.. Or Romney could once again
But for a candidate trying to command national attention during the lazy days of August, the benefits of hitting the road outweigh the risks. The bus tour allows a candidate to combine old-school, grassroots campaigning with a themed message that can capture the attention of the national media and thus, a national audience.
"It is sort of a last vestige of retail politics," said Rick Davis, who served as campaign manager for John McCain's 2008 and 2000 presidential campaigns.
As Romney teases out the days before he announces his vice presidential pick and awaits the Republican National Convention in Tampa, he's embarking on a four-day trip Saturday through Virginia, North Carolina, Florida and Ohio. The theme of the bus tour is "the Romney Plan For A Stronger Middle Class."
As he makes his way through the swing states, Romney will meet up with a few potential running mates, including Ohio Sen. Rob Portman and Virginia Gov. Bob McDonnell. That makes it , something McCain did in 2008. After McCain surprised the nation by announcing Alaska Gov. Sarah Palin as his running mate, they hit the road -- and soon made a pit stop for ice cream at the Dairy Duchess in New Concord, Ohio.
The impromptu stops at places like ice cream parlors are "part of the charm" of the bus tour, according to Davis. The former campaign manager should know a thing or two about the matter: "I've spent half my natural life on my buses," he said.
While some bus tours are notable for their flamboyant decor or custom security features (like President Obama's high-tech, $1.1 million bus, Ground Force One), Davis said the McCain bus was known for "very strong coffee and abundance of donuts and candy" to satisfy the Republican candidate's sweet tooth.
For logistical reasons, the bus tour is especially effective for a presidential candidate like Romney, who is past the primaries but has yet to become the official nominee.
During the primaries, a candidate can easily stop at small venues, such as a restaurant that's a favorite among the locals. Once a candidate gets Secret Service protection, however, those trips become much harder. Furthermore, Romney needs an efficient way to travel, since he can't spend money he's raised for the general election until he officially accepts the nomination at the Republican convention on August 27.
"Most campaigns don't elect to pull out the 737 and the gas check card," Davis said.
While cheaper than some other options, a bus tour is by no means a modest affair. The candidate usually has a couple of buses reserved for the press, a bus for staff and potentially more for his family.
"It's become the status symbol of American politics, you've got to have your own bus," Davis said, noting that McCain's daughter Meghan had her own bus in 2008 and McCain's wife Cindy had one for a while. Even high-profile supporters like sports stars can get their own buses.
"It's almost like the hierarchy of the campaign comes down to whether you can garner your own bus as a surrogate," Davis said. "There's been an explosion of buses these days."
The bus tour -- and even the concept of national retail politicking -- is a 20th century phenomenon, said presidential historian Doug Brinkley.
"Retail politics used to mean next to nothing until the advent of Theodore Roosevelt," Brinkley said.
The nation's 25th president, William McKinley, even ran a "front porch campaign," Brinkley said, where he never left his house in Ohio and voters came to him. Once railroads were in place, however, Roosevelt was able to travel across the West to gear up for his 1904 campaign, and "things have never been the same since," Brinkley said.
Jimmy Carter introduced the era of customized campaign buses, Brinkley said, though Ronald Reagan harkened back to an earlier time with a train tour in 1984. These days, however, trains simply don't go to the media markets that candidates want to target, Davis said.
"You've got to be able to go to the locations where you can dominate the local news that day," he said. "When you roll in Dayton, Ohio you want to know you're going to own Dayton, Ohio that day, and a bus rolling in will do that."