CLEVELAND — In Florida, a state trooper pulled Jim Wilson off the highway, but instead of issuing a speeding ticket, asked a favor: Could he have a few Romney for President bumper stickers?  In Michigan, a woman left a handwritten letter for Mitt Romney on Mr. Wilson’s dashboard, recounting her husband’s trouble finding work. “We pray you can get us out of this mess,” she wrote.  And here in Ohio, three young men surrounded Mr. Wilson’s car, repeated a crude anti-Romney chant and broke his driver’s side windshield wiper.  The cocoonlike machinery of the modern presidential campaign, with its bulletproof motorcades, private planes and handpicked audiences, has kept Mr. Romney largely insulated from the public’s raw reactions to his candidacy.  The same, however, cannot be said for his most fanatical supporter, a 69-year-old former life insurance salesman and an unabashedly anti-Obama Republican from Virginia.  For the past year, Mr. Wilson has devoted himself with the single-mindedness of a college-age groupie to following Mr. Romney around the country in decidedly conspicuous style: driving a pickup truck festooned with 27 giant Romney for President posters. (The largest are the size of a refrigerator.)  Forgoing home-cooked meals and forbearing horrendous traffic, he has driven, sometimes nonstop, from Omaha to Charlotte, N.C., (19 hours), Portsmouth, Va., to Tampa, Fla., (14 hours) and Des Moines to Manchester, N.H., (22 hours), showing up, almost without fail, just in time to greet guests outside of a Romney event.  In the process, Mr. Wilson and his truck have become a kind of mobile barometer of the candidate’s popularity, or lack thereof, in an era of hyper-partisanship.  There were the workers in Detroit, who he said backed a garbage truck into to his white 1998 extended-cab GMC 1500, leaving an ugly gash. There was the woman in Illinois who tearfully handed him a plastic rosary, intended as a gift for Mr. Romney. And there were the tomatoes splattered across his windshield. “I don’t remember which state that was, but I know they were ripe, so it must have been the South,” Mr. Wilson said during an interview from inside his truck, as it rumbled across Ohio not long ago.  Mostly, though, the feedback can be broken down into two categories: a raised thumb or an outstretched middle finger. “These days,” he said, “the thumbs up are vastly outnumbering the third digits. I like that.”  To those who contend that Mr. Romney does not inspire the same kind of deep-seated, drop-everything dedication as, say, Barack Obama in 2008, Mr. Wilson is a four-wheel rebuke. Since last summer, he has logged about 40,000 miles, visited 15 states and attended 150 campaign events on Mr. Romney’s behalf.  “I don’t think anyone has as much sweat equity in this sucker as I have,” Mr. Wilson said.  He made the decision to spend 11 months of his life shadowing Mr. Romney on something of a whim. In July, he met the former Massachusetts governor at the Iowa State Fair, terrain that Mr. Wilson knew well from growing up on a hog and cattle farm in the state, where his father and godfather had been active in Republican politics. He had dabbled in campaigns himself, mostly in Virginia, as a volunteer.  He liked what Mr. Romney had to say about free enterprise and federal regulation, and he could never muster much interest in Newt Gingrich (“his time has passed”) or Rick Santorum (“a little whiny”). But more than anything, he hated what he believed Mr. Obama stood for: big government run amok.  “I mean, is there no facet of our government into which this president has not poked his nose or hands?” he asked.  On the cusp of his eighth decade, with his finances secure, no family at home and health intact, Mr. Wilson realized something else. This could be his last political campaign. So why not go out with a bang?  A Vietnam veteran whose legal name is Norris Aubrey Wilson II, he is an unlikely mascot for the buttoned-up, rules-obsessed Mr. Romney. Mr. Wilson is frequently profane (cycling through jokes about weight, Viagra and Rogaine), smokes a pipe, carries a fish-skinning knife with a three-inch blade and dons an almost cartoonishly retro wardrobe of knee-high tube socks, bright white sneakers and “Magnum, P.I.”-era Tom Selleck beige shorts.
Jim Wilson, who drives his pickup truck around the country to campaign for Mitt Romney, has become a charming counterpoint to a sometimes awkward candidate.