ST. LOUIS • The beginning of the end of Tim Pawlenty's presidential campaign came in June, when his failure to attack frontrunner Mitt Romney was viewed in some corners as lacking the killer instinct to go the distance.

Pawlenty employed the phrase "Obamneycare" to tie his GOP rival's record as governor of Massachusetts to the president's own healthcare plan.

But, when given the chance to level the same attack at Romney in a debate, the former Minnesota governor backed off, a "whiff" that may have helped precipitate his exit from the race.

Eight months later, at least two of Pawlenty's former campaign aides are now working for Missouri Senate hopeful John Brunner, whose maiden debate performance Saturday was notable for what transpired away from the platform.

This weekend's Lincoln Days was the first time that all three Republicans vying for the party's Senate nomination — Brunner, U.S. Rep. Todd Akin and Sarah Steelman — appeared together in one forum.

The debate was described as cordial, at least on stage.

However, shortly before the debate ended, the campaign of Brunner, who served as an infantry officer in the Marine Corps, delivered a surprise attack, issuing a news release describing Steelman as a "Cut, Copy and Paste" Republican.

Brunner's campaign said the style of the forum — a moderator quizzing the candidates, who had no opportunity for rebuttal — did not lend itself to throwing jabs.

The campaign also felt the need to respond to Steelman unveiling her platform, which was done at an event at Kansas City's World War I memorial the day before the debate.

Even so Steelman, the only one of the GOP Senate contenders who has run (and won) a statewide campaign, was taken aback by Brunner's post-debate salvo.

"That's too bad that he didn't have the guts to bring it up at the forum we were just at," Steelman told the Associated Press when confronted with Brunner's news release. "Maybe he's worried about me."

Maybe so — but perhaps he should be just as concerned by the perception of a candidate who, given the choice for a face-to-face fight, throws a rock from the flank.

It didn't work out well for Pawlenty.