Iowa Republicans have some interesting races today, including former governor Terry Branstad vs. Bob Vander Plaats in the gubernatorial primary, as well as picking nominees among crowded fields to run against potentially vulnerable Democratic House incumbents Dave Loebsack and Leonard Boswell. Meanwhile, Iowa Democrats are picking their sacrificial lamb to go up against Sen. Charles Grassley.

Unsurprisingly, the Republicans are motivated to come out on primary day:

Far more Republicans than Democrats are voting in today’s Primary. Thunderstorms have marched across the state, perhaps prompting some voters to delay a trip to their polling place. However election officials in eastern, central and western Iowa say turn-out trends for Republicans already are much higher than for Democrats because of interest in the Republican race for governor . . . The state’s commissioner of elections expects between 150,000 and 175,000 Republican ballots to be cast in today’s Primary and about 100,000 Democratic ballots.

UPDATE: Here’s a small example from an Iowa radio station: “Polk County Voter turnout update: as of 3 p.m. Republicans 16.58 percent (12,273); Democrats 4.2 percent (4,583).”