Delegates Count, but How do you Count Them?

"The vote reporting in many places by congressional district is quite slow," explained NBC NewsDirector of Elections Sheldon Gawiser. "This is most often the case when congressional districts span county lines, but it can also occur when multiple congressional districts are in a county. The worst case is when there are partial multiple counties in a congressional district, which is less common."

We know that Clinton, for instance, won Contra Costa County in Northern California. But Contra Costa County encompasses parts of three different congressional districts.

Within Orange County, which Clinton also carried, are parts of six different congressional districts.

"Because of the delegate-allocation rules, we often need all the votes in to be sure we know what the allocation would be in the district," Gawiser said.

Even awarding the statewide delegate winners, Gawiser said, might seem easier than it is in reality.

"We need to know the actual final vote percentage to be sure we have the at-large allocation correct. In some cases, it is easy, but when a candidate is just on the edge of one additional delegate, then it takes virtually all the vote to be in," he said.

Caucus confusion
Adding to the complexity are caucus states like Minnesota, Iowa and Kansas, where meetings of local party activists determine delegates.

And caucuses go through several steps before those delegates are chosen.

In Iowa, the delegates elected at the precinct level on caucus night then move on to the county convention in their respective counties.

At the county conventions, delegates are then elected and head off to the congressional district convention and the state convention.

The district conventions, in turn, elect delegates to the national convention, which is where the party's nominee is chosen.

The state convention also chooses some delegates to the national convention.