With 3/4 of the precincts reporting, Rick Santorum is leading with nearly 50% of the Republican vote. Romney has 26%, Gingrich 16%.

Update 10:18 pm CDT: That margin looks like it will hold. See TheHayride’s analysis here.

Incumbent President Barack Obama has 72% of the Democratic vote against a powerful field that includes Bob Ely, Darcy G. Richardson and John Wolfe.

Unofficial tally here.

Open thread.