You know the McCain campaign is taking a board-game approach to the presidential campaign when its moves come straight out of a game of Clue: “Gov. Pawlenty … in Iowa … with the tire gauge.”

On Saturday Gov. Tim Pawlenty brought his rolling attack-dog-in-training-and-pony show to Iowa, where he helped roll out what’s apparently a key GOP prop for this week: a tire gauge. As our sister site the Iowa Independent reports, Pawlenty wielded the gauge along with some sharp-tongued rhetoric lambasting Sen. Barack Obama for recommending Americans conserve fuel by checking their vehicles’ tire pressure.

Attacking that bit of common- sense, Joe Six-Pack advice is apparently the Republican talking-point successor to last week’s sharp veer to the negative, with “Celeb” and “The One” ad slams on Obama for being popular. Pawlenty has been riding the ups and downs of the Republican veepstakes like a bungee jumper as he auditions across the country for the traditional VP hatchet-man role. (Another T-paw line from Iowa: “Voting for Obama is the political equivalent of bungee jumping.”)

When Pawlenty debuted as a serious contender on the network chatfests in late June, his problem was speak softly and carry a small stick. Buzz over his being in the run for John McCain’s running mate has upped the volume, but his choice in props still qualifies as a small stick. If he’s going to impress veteran hatchet men like one-time veep candidate and former Sen. Bob Dole or the current president’s father at the Republican National Convention, McCain might need to switch to a tire iron.

This is the first gimmick of Pawlenty’s, rhetorical or otherwise, that’s caught on; maybe he just needed a prop to take the emphasis off his uninspired stump presence. Something heavier-hitting than these soft trial balloons to reduce his "boring" quotient:

- “I think Barack Obama’s book ‘The Audacity of Hope’ perhaps should be retitled ‘The Audacity of Hypocrisy’” [on ABC’s “This Week With George Stephanopoulos”]

- “They shouldn’t have had the meeting in Unity, N.H.; they should have had it in Political Expediency, N.H., if there is such a community.” [After Obama and Hillary Clinton’s joint event in New Hampshire]