Iowa Republican officials expect results for the first 2012 presidential caucuses to begin coming in as early as 8:30 EST tonight, with a final tally expected around 9:45 p.m.

Registered GOP voters will choose their presidential candidate in a single round of secret ballot voting at 1,774 precinct caucuses around the Hawkeye State. Each precinct will report the results to the state party, which will publish the final results later in the evening.

The ballot is not binding but provides the first official step on the presidential primary calendar. The previous two presidents won the Iowa caucuses before receiving their party’s nod.

Some local GOP operatives estimated that turnout would hover around the 2008 caucus participation level, about 120,000 people, but other operatives said that figure could be as high as 140,000. State Republican Party officials declined to estimate turnout.