Former DFL candidate for governor Matt Entenza launched a surprise campaign against the DFL state auditor, filing for the office just moments before Tuesday's deadline.

"The auditor's job is about more than just balancing the books," said Entenza, who poured more than $5 million of his own money into his 2010 quest for the state's top office. He came in third in a three-way primary won by Gov. Mark Dayton.

Entenza, a former House minority leader who ran for attorney general in 2006, said he would run the auditor's office as Dayton did in the 1990s by taking a deeper look at key issues that trouble local governments.

The auditor's office was a springboard to the governor's office for Arne Carlson as well as Dayton.

Although Entenza said he had sent two-term DFL auditor Rebecca Otto a note informing her of his plans, she said the end-of-the-day filing came as a surprise. She said Entenza's sudden decision — he said he decided to run Tuesday — will not change her plans and will cause her little challenge.

"Democrats are very happy with the work that I've done," she said. "They're very proud of the work that I've done."

She won party endorsement Saturday with no opposition.

DFL Party Chairman Ken Martin was less sanguine about the intraparty challenge.

"His last-minute filing is an insult to the hardworking DFLers he has to win over," Martin said in a news release. "The DFL takes the endorsements of its candidates seriously and will put the full weight of its party resources behind Auditor Otto's candidacy. I am confident that she will prevail in the primary and general election."

There's a bit of history in Martin's harshness. He was former Attorney General Mike Hatch's campaign manager when Hatch ran for governor in 2006. That same year, Entenza's campaign to replace Hatch as attorney general imploded after it came out that Entenza had done opposition research on Hatch.

Entenza said, if he wins, he would concentrate on protecting pensions, making sure that local governments are not bullied into giving corporate tax breaks that pit one Minnesota city against another, and looking into school spending to close the racial achievement gap. He also said Democrats "should look at the values that the auditor holds."

A decade ago, he said, Otto voted for a constitutional amendment to ban same-sex marriage and supported the idea of voter ID.

Of those votes, Otto said, "this is a state auditor job."

Rachel E. Stassen-Berger

Twitter: @rachelsb