OK, we all know that primary elections - held in early February, when gloomy gray skies are often overhead — tend to attract few voters.

But despite the low turnout, the numbers that emerged from two local house races Tuesday give, we think, additional credibility to the notion that there’s an anti-incumbent stew simmering out there.

In the 5th state house district, for example, incumbent Rep. Ken Dunkin scored about 44 percent of the vote. Do the math: That means 56 percent of voters chose another candidate. Most of those votes went to South Loop lawyer David Schroeder, who ran a credible, smart campaign. Dunkin, who faced challengers Tuesday for the first time in three primaries, probably won’t have that luxury going forward.

Likewise, in the 10th, incumbent rep Annazette Collins won with just around 35 percent of the vote. Candidate Jonathan Goldman ran strong here, with 24 percent.

It’s difficult to say how the dynamic in the 5th translates into the aldermanic campaigns that are literally just around the corner. Local state reps are fairly low on voters’ priorities. (That cynicism can be partly forgiven: Most of us know well at this point that Speaker Madigan, when he’s not lobbying for tax breaks for large commercial property owners, controls everything in Springfield.)

In the end, the incumbents were re-elected. And you can be sure the current aldermen who represent neighborhoods in and around the Loop will fight to do the same. But it may be a stickier campaign season than they had hoped for. Stay tuned.

By the way, perhaps the juiciest prediction we heard among political analysts watching the returns roll in last night was that David Hoffman, the former Chicago inspector general bested by Alexi Giannoulias as the Dem’s choice for U.S. Senate, will run for mayor in 2011. That this whole Senate race was mainly a tactic to get his name out there.

Did he do that? Will Hoffman run? As we said: Stay tuned.