There are (at least) two articles out today exploring all the competition Dino Rossi has in trying to become the Republican who gets to take on Democratic Senator Patty Murray this fall.

Salon focuses on the threat posed by the Sarah-Palin-endorsed Clint Didier:

With all the attention focused on Rossi Wednesday, we at Salon figured it was worth taking a look at Didier, too. Because, frankly, if his campaign Web site is any guide, he's the far more interesting candidate.

True enough. It's not every day you get to write about a former NFL tight end who's now a subsidy-slurping, government-handout-bashing, Tea-Party-courting alfalfa farmer.

Meanwhile, the Spokesman Review takes a look at all the rest of the challengers: the state senator (Don Benton), the chiropractor (Sean Salazar), the energy trader (Craig Williams), and the titan of Bellingham (Paul Akers).

Here's the thing: although this whole collection of would-be Murray-slayers makes for an incredibly entertaining cast of political climbers, they've all got one big problem. It's called the top-two primary.

Unlike other states, where Republican establishment favorites have had to tangle with Tea Party insurgents (and, presumably, a few chiropractors and small-town titans, too) in messy "closed" partisan primaries, Washington's current primary system throws everyone onto the same ballot and lets the top two vote-getters, regardless or their party, advance to the general.

So, theoretically, it could end up being Didier vs. Rossi in November, or even Akers vs. Salazar. But in reality, barring some big Rossi implosion over the next few months, it's almost certain to end up being Murray vs. Rossi.

That's because the top-two primary favors familiar candidates in situations like this, and Rossi—with his two failed attempts at the governor's mansion over the past six years—is, if anything, familiar.