Experts say the most expensive gubernatorial primary in Minnesota history is likely to become the state’s most costly race for governor.

Campaign finance reports released Tuesday show the four major candidates have spent more than $7.5 million in 2010 alone, according to the Minnesota Campaign Finance and Public Disclosure Board.

In the 2006 governor’s race, incumbent Tim Pawlenty and his DFL opponent Mike Hatch spent a total of about $7.9 million.

In this race, DFL Candidates lead in terms of contributions. Matt Entenza has raised about $4 million, leading Mark Dayton by about $1 million and the party endorsee, Margaret Anderson Kelliher, by about $3 million. Republican candidate Tom Emmer is trailing Kelliher by about $200,000.

Entenza and Dayton have personally contributed more than $6.3 million to their campaigns this year.

Dayton explained he financed his own campaign in order to remain independent from lobbyists and private interests.

But David Schultz, a professor of public policy at Hamline University, disagreed.

“Rich candidates who spend on their own behalf always make that statement,” he said. “They always want to say that they’re not bought and paid for, and that they’re their own person. Whether or not that’s true, that’s something for the voters to ultimately decide.”

Schultz called the race “record-setting” at a national level.

In Entenza’s case, spending has led to some gains in the polls, Schultz said.

Campaign spokesman Jeremy Drucker said spending, including more than $1 million in TV advertisements, is intended to increase Entenza’s name recognition. He noted Entenza is neither a former U.S. senator nor the Speaker of the Minnesota House of Representatives.

Kelliher raised about $770,000 in individual contributions, the most of any candidate. Republican Tom Emmer followed her closely with roughly $755,000 from individuals.

However, Kelliher took roughly $170,000 more from lobbyists and political action committees than the next highest candidate, Mark Dayton.

Kelliher has consistently stressed her grassroots campaign as a strength, and Schultz agreed.

A primary win by either Dayton or Entenza could outflank Emmer in sheer spending power, forcing him to rely on independent expenditures by third party groups rather than direct contributions to finance expensive TV ads, Schultz said.

Entenza has about $130,000 cash on hand, the lowest of any candidate. In 2010, he had about $3.9 million in campaign expenditures.

“Anybody who wants to think that Minnesota is not a big money state in terms of politics, this is the third example in the last two years to show how much money is thrown around in Minnesota,” Schultz said.

Currently, Emmer has about $300,000 available after spending about $500,000 this year.

Kelliher and Dayton hover at the low and high $300,000 marks respectively, but Kelliher was outspent by about $2 million.