[SCROLL DOWN for updated vote totals]

A key race for conservatives as incumbent Joe Schwarz is backed by the party regulars, including the President, while challenger Tim Walberg is supported by the Club for Growth.

So far, only Branch County is reporting any precincts. Walberg leads with 48.7%, followed by Schwarz at 33.5%. I presume there are other candidates to make up the difference . . .

No word on % of precincts yet. The official "unofficial" Michigan results site is HERE.

UPDATE 11:41: Hillsdale County reports some results - new totals: Walberg 54.8% 6252 votes, Schwarz 30.1% 3436 votes

I don't know if these early counties were predicted to be Walberg, but he is building a strong early lead.

CORRECTION: Walberg was NOT on the RightRoots list of endorsees. He is backed by Club for Growth. I've corrected the lede.

UPDATE: No further results posted by the Michigan Department of State yet, but FlashReport has a contact with Club for Growth claiming a big win. Can't disprove that by what we've seen so far.

UPDATE 1:00 a.m.: Maybe the CFG knows something we don't, but the last posted returns from Calhoun County make the race much closer: Walberg still leads with 10,419 votes and just over 41%, while Schwarz now has 9084 votes and 35.8%. Still waiting for returns from Eaton, Jackson, Lenawee, and Washtenaw Counties.

UPDATE 1:07: Jackson County is in, and the totals now are: Walberg, 42.0% on 18,437 votes; Schwarz 36.1% on 15,861 votes. I apologize for not being more knowledgable about the outstanding counties, but I can't say if they might tend toward one or the other candidate.

UPDATE 1:47: I'm NOT sleeping on the job, the official site hasn't updated yet. Waiting on Washtenaw, Lenawee, and Eaton Counties.

UPDATE 2:00: Eaton's in! A big county . . . new totals: Walberg 23,469 votes for 39.9%; Schwarz 21,822 for 37.1%. Could be a long night . . .

UPDATE 2:24: ABC News has called the race for Walberg. They give him 26, 295 votes to Schwarz' 21,697 with 77% reporting. Forbes concurs.

UPDATE 2:33: No new totals on the Walberg-Schwarz contest, but on the Democratic side, Sharon Renier has won the right to challenge for the seat with a clear majority. Only about 13,000 votes total in the Democratic Primary so far, though, so the GOP winner should have an easy time of it.

UPDATE 3:30: Lenawee County is in, finally - big for Walberg! The totals are now: Walberg 29,156 - Schwarz 24,391. With only Washtenaw County still out, it will take one heckuva comeback for Schwarz to win.

UPDATE 4:11: Washtenaw County still isn't up on the state site, but they have reported their results. Schwarz wins by nearly 1000 votes, but it isn't enough. Walberg wins the primary.