Fast approaching their party's endorsing convention, DFL candidates for governor Wednesday trotted out endorsements, a new TV ad buy and even underwear in an effort to gain an advantage.

Meanwhile, the leading Republican candidates locked horns when the campaign of Rep. Marty Seifert sent a letter to delegates reminding them of rival Rep. Tom Emmer's drunken-driving arrests from 20 and 30 years ago.

Crying smear tactics, Emmer's campaign released the four-page letter from a woman they identified as a Seifert supporter that referenced the arrests and lamented that her husband and son were seriously injured by a different drunken driver. The letter was addressed to "fellow Republican delegates" and claimed that Emmer hadn't fully addressed his drunken-driving problems during the campaign.

Emmer's campaign denied that claim. "It's ... something that Tom has been upfront about, something he takes extremely seriously," said spokesman Ben Kruse.

Emmer said his record has long been public and that he has talked to any delegate who has asked about it. He also said his past is part of what makes him who he is. "I do think it's important for people to know," he said. He said his punishment should have been tougher, perhaps then "I probably wouldn't have taken the second chance."

That Seifert brought it up at all, "I feel for Marty ... it's too bad," Emmer said.

Seifert's campaign defended releasing the letter. "Sandra's letter provides factual information about a vital issue for the delegates to consider: the electability and credibility of candidates," campaign manager Kurt Daudt wrote in an e-mail. "At her request, the Seifert campaign distributed her letter."

Seifert said the letter and Emmer's legislative record on DWI laws are "fair game."

He said Emmer's past drunken-driving arrests are not a disqualification but are "relevant to the delegates."

The GOP endorsement will take place next Friday.

DFL efforts

On the DFL side, Rep. Tom Rukavina's campaign said it will sell boxer shorts with a union logo to underscore the message that Rukavina buys American -- right down to his underwear. The skivvies will bear his campaign slogan, "Refreshingly Honest."

More conventional politicking was being done by House Speaker Margaret Anderson Kelliher, who announced that Minnesota Farmers Union President Doug Peterson, a former House legislator, would endorse her bid for DFL endorsement.

"Margaret understands real rural issues and has the leadership style to bring rural, urban and suburban people together," Peterson said in a news release.

Meanwhile, Peterson's son, former DFL Rep. Aaron Peterson, endorsed former House Minority Leader Matt Entenza for governor. He cited Entenza's promotion of renewable energy.

U.S. Rep. Betty McCollum announced she will back Minneapolis Mayor R.T. Rybak for governor. "I believe your campaign is best positioned to successfully carry the DFL endorsement through the August primary election and on to victory in November," wrote McCollum.

Javier Morillo-Alicea, president of a Minnesota local of the Service Employees International Union, also gave his nod to Rybak, though the organization is formally holding back its endorsement until after this weekend's DFL convention.

Some DFL candidates were preparing to wage a primary fight if they don't win the endorsement. Entenza unveiled details of his new TV ad, scheduled for next week, that sounds his theme that Minnesota is backsliding and needs to spend more on education and emphasize renewable energy "so we can get our economy moving."

Staff writers Baird Helgeson and Rachel Stassen-Berger contributed to this report. Pat Doyle • 651-222-1210