Wait, didn't Nevada already vote on Jan. 19? Yes, but Hillary Clinton's narrow victory wasn't the end of Nevada's nominating process. As CQ's Marie Horrigan reports, the state has a three-step system, and the precinct caucuses, which Clinton won, were just the first step. The second was the Feb. 23 caucuses in Nevada's 16 counties, of which Obama won 15. But voter turnout was so large in Clark County (which includes Las Vegas) that the two campaigns agreed to hold a redo seven week later -- tomorrow.

Horrigan explains:

Clark County is, by far, the largest county in Nevada with 1.8 million of the state's 2.4 million residents. It encompasses Las Vegas, which itself has 545,000 residents including a significant population of union service workers. Democrats are gaining ground in voter registration in the state, making Nevada a key battleground for the general election. And, with the Democratic primary contest still up in the air, every delegate counts....

The delegates to the county conventions were allocated based on the results in the precinct caucuses. Clinton entered the Feb. 23 contest with 4,055 delegates vs. 3,308 for Obama, according to a spokeswoman for the Nevada Democratic Party. Delegates to the statewide convention are allocated based on the results of the county caucus, and delegates to the Democratic National Convention in August will be elected at the state party convention [on May 17].

Clark County has more than half the delegates to the state convention...

None of the delegates to the conventions are pledged, which means that over the past seven weeks, delegates may have decided to support a different candidate than the one they chose in January.

Just another wrinkle to consider.