There's a rare forecast for top Republican primaries: Competitive

For Minnesota Republicans, next year's calendar will have an unfamiliar look.

First, there will be the usual endorsement battles, when a few thousand activists attend conventions and make their choices about which candidates should represent the party, and eventually there will be the November battle against Democrats.

But in between, Republicans will have to circle Aug. 12 on their calendar. That's the date of the state's primary, which will likely feature heated battles among those who would oust Gov. Mark Dayton and Sen. Al Franken.

High-profile Republican candidates in all those races have suggested or said outright that they would continue running whether or not they have the party's nod.

The breadth of the expected intraparty battles will be a clear change for Republicans.

Eric Ostermeier, who writes at the University of Minnesota's Smart Politics blog, found that competitive primaries among Minnesota Republicans in premier contests are rare.

"Republicans have not had a competitive primary in a gubernatorial race in nearly 90 years," he wrote.

With the exception of last year, when Republican endorsee Kurt Bills won the primary with just 51 percent of the vote against low-profile challengers, competitive Republican primaries for U.S. Senate have been "virtually unheard of during the last 75 years," Ostermeier found.

But next year will change that.

Former Lazard Middle Management executive Mike McFadden, state Rep. Jim Abeler, state Sen. Julianne Ortman, St. Louis County Commissioner Chris Dahlberg and former candidate Monti Moreno are preparing for an expected Republican U.S. Senate primary.

Five GOP candidates for governor — former House Speaker Kurt Zellers, state Sen. Dave Thompson, Hennepin County Commissioner Jeff Johnson, teacher Rob Farnsworth and businessman Scott Honour — are already vying for 2014, several with their sights on a primary contest.

Republicans may also end up with a primary in the heavily GOP Sixth Congressional District race to replace U.S. Rep. Michele Bachmann, who won't be seeking re-election.

Witness the Democrats in 2010 and 2012.

In 2010, Dayton vied against two other well-funded Democrats in the primary race. The trio, which featured DFL-endorsed former House Speaker Margaret Anderson Kelliher and former state Rep. Matt Entenza, battled through the summer. They appeared at events across the state, launched advertising campaigns and netted media coverage for their contest. They fought without inflicting deep wounds, became better known and improved as candidates as a result.

Republican Tom Emmer, meanwhile, had a fairly clear shot from party endorsement to November. He was many Democrats' only target, whereas Republicans had to scatter their scorn among the three.

Dayton narrowly won the August race and narrowly defeated Emmer in the fall.

Two years later, Democrats again ponied up a primary worth watching. In the quest to oust Republican U.S. Rep. Chip Cravaack in the northern Eighth District, three Democrats canvassed the district for votes through August. Ultimately, former U.S. Rep. Rick Nolan bested his rivals and tossed Cravaack from office a few months later.