CANNON FALLS, Minn. — President Barack Obama launched a rare direct attack Monday on the GOP presidential field, criticizing Republican hopefuls for what he contended was their blanket opposition to any compromise involving new taxes.

“Think about that. I mean, that’s just not common sense,” Obama said at a town hall-style meeting in Cannon Falls, Minn., as he kicked off a three-day bus tour through Minnesota, Iowa and Illinois.

“You need to take a balanced approach,” he said.

Obama made the comment after describing a moment in last week’s GOP presidential debate when all eight of the candidates participating said they would refuse to support a deal with tax increases, even if tax revenues were outweighed 10-to-1 by spending cuts.

Obama didn’t mention any of the candidates by name, and started the remark by saying, “I know it’s not election season yet.”

But his comment underscored that election season is well under way. And the bus tour itself, although an official White House event rather than a campaign swing, took on a campaign feel coming on the heels of Republican Michele Bachmann’s weekend victory in the Iowa Straw Poll and through states Obama won in 2008 but where he now needs to shore up his standing and counter GOP attacks.

It also comes after the president spent much of the summer holed up in the nation’s capital enmeshed in bitterly partisan negotiations on the debt crisis that cratered his approval ratings and those of Congress amid a faltering economy and high unemployment.

In response to a question, Obama also took the chance to counter the anti-big-government stance embraced by the tea party and largely by the Republican presidential field.

He noted that although government doesn’t do everything well, it’s also responsible for sending a man to the moon and for the military defending the country, among other things.

“When you go to the National Parks and those folks in the hats, that’s government,” Obama said.

“As frustrated as you are about politics don’t buy into this notion that somehow government is what’s holding us back,” he said.

He made clear he believes Congress is responsible for that, at least in part, accusing lawmakers of putting politics ahead of the country and calling on voters to tell them to cut it out.

“You’ve got to send a message to Washington that it’s time for the games to stop, it’s time to put country first,” Obama said.

“If you can do the right thing, then folks in Washington have to do the right thing,” the president said. “And if we do that, there is not a problem that we face that we cannot solve.”

Eager to get out of Washington, Obama struck a casual tone, ditching his suit and tie for a sports coat and khakis for the open-air event.