ST. PAUL  — In presidential politics, Minnesota is as close to a Democratic fortress as states come.

It has tantalized Republicans in recent presidential campaigns, but it’s still wound up as general election fool’s gold for the GOP ever since Richard Nixon last won it for the party in 1972.

So it’s easy to understand why Minnesota Republicans are basking in the presidential glare now. For Tuesday’s caucuses at least, they have the spotlight to themselves — and a genuine piece of the action.

This year’s Minnesota caucuses drew their first significant attention from the contenders in memory, with all four hopefuls dropping by in the final week. Front-runner Mitt Romney stopped in last week, while Newt Gingrich, Ron Paul and Rick Santorum were in town as late as Monday.

Usually, the Republican nomination fight is wrapped up well before voters in the wintry enclave get a say. Or the primary calendar lumps Minnesota with states that offer bigger prizes.

Republican caucus attendees tend toward the conservative, especially those most concerned with social issues. Tea party members stormed the caucuses two years ago and could play a role this time, too.

A straw ballot will crown a winner Tuesday night, but delegates to the summer’s Republican National Convention won’t be decided for several more months.

Four years ago, more than 60,000 Republicans turned out and Romney trounced eventual nominee John McCain. That more than doubled attendance from 2004, but was overshadowed by the more than 200,000 Democrats who headed to their caucuses to give Barack Obama a 2-to-1 win over Hillary Rodham Clinton.

Turnout at the state’s caucuses tends to be a tiny fraction of eligible voters in a state that prides itself on nation-leading fall participation. Minnesota used to have a primary rather than a caucus, but that was abandoned more than a half-century ago.

In Minnesota, voters don’t register with a party designation. So on caucus night, people can participate in any party caucus they want at hundreds of schools, community centers and other locations. And they have a host of choices: the Independence Party, the Democratic-Farmer-Labor Party and several minor parties all had a chance to put on caucuses.

With Obama a shoo-in for the Democratic nomination, all eyes are on the GOP results. There was a sense among party veterans that the big four were tightly bunched and turnout would dictate the winner. A lower turnout favored Santorum and Paul because of the intensity of their support among religious conservatives and anti-war Republicans, respectively.

Even Romney’s top Minnesota surrogate, former Gov. Tim Pawlenty, wasn’t ready to predict the former Massachusetts governor would score a second straight win here.

“It will be very competitive. I can’t tell you who will come out on top,” Pawlenty said Monday.

The caucuses start at 7 p.m. CST and nearly complete results are typically known within a few hours.