Will primary voters go with their hearts or minds?

I know there are voters out there in Snohomish County trying to decide whether to let their heart or their mind guide them in this primary.

Which they follow may lead to a few surprises.

Special interests on the left and right as well as the Democratic and Republican parties are making the choice more difficult. With stakes to protect, these political forces are bankrolling efforts aimed at tugging voters in one direction or the other.

Take the competition between Republicans Clint Didier and Dino Rossi in the race for U.S. Senate.

While portrayed as the tea party favorite (Didier) versus the Republican Party establishment choice (Rossi), it's broader than that.

Rock-ribbed conservatives -- be they social, fiscal, religious or constitutional -- are aligning with Didier to flex their ideological muscles and vent frustration with the Democratic regime in Congress.

Emotionally, Didier's got the principle and passion these voters have not seen in many of their party's candidates in a while and desperately desire.

Yet, they realize the practical choice is Rossi. Despite his not having won an election in a decade, he is the professional politician with the best chance among GOP challengers to unseat Democratic Sen. Patty Murray in November.

These conservative Republicans don't miss many votes. With a low turnout predicted, they will be a sizable bloc of those casting ballots for Republicans -- making the outcome of their decision so important.

Do they follow their hearts, stand on principle and possibly push Didier into the top two where he'd face long odds of defeating Murray? Or do they wince, back Rossi, cross their fingers he's elected and then set about pulling him closer to their views.

There's a tug-of-war on the other side of the political spectrum in races for two state legislative seats in Snohomish County.

Organized labor is bankrolling much chronicled campaigns to oust two Democratic state senators they've helped in past elections: Jean Berkey in Everett and Steve Hobbs in Lake Stevens.

Against Berkey, unions representing state employees, teachers, health care workers and the trades are going all out to replace her with Nick Harper, a liberal Democrat.

Against Hobbs, they aren't pushing as hard or spending as much because the replacement options aren't quite as attractive. They are trying nonetheless.

Both efforts are intended to elect people they think will better defend and promote principles important to organized labor.

Democrats are the unions' traditional allies but having a majority of them in the Legislature has not produced the gains expected on collective bargaining and workplace organizing. Wages aren't rising, benefits are falling and Democratic leaders repeatedly flinch at trimming corporate tax breaks that might free up money for workers.

There is danger in the strategy. If they fail to unseat Berkey and Hobbs, those two could oppose their every move in the next session. And if they do get them out there's no guarantee the successors will be better. But they're convinced it's worth the risk.

For them, as well as the patriots engaged in the Senate race, this primary is about standing for something rather than not standing at all.

They've made up their minds to put their hearts into it -- and hope voters will too.

Political reporter Jerry Cornfield's blog, The Petri Dish, is at www.heraldnet.com. Contact him at 360-352-8623 or jcornfield@heraldnet.com.