There are also some 2,400 vacant delegate slots to be filled with alternates because paperwork was incomplete or missing, or because people weren't elected at the caucuses to fill the candidates' delegate positions. The campaigns and the party must fill all alternate slots by March 25.

Clinton's campaign has about 1,300 vacant slots to fill, while Obama's has about 1,100, according to state party Deputy Executive Director Kirsten Searer.

The county convention on Feb. 23 was disbanded when more than 10,000 people swamped too-small meeting facilities at Bally's, leading to chaos and fear by both campaigns that the result wouldn't be fair.

In the new convention, only those with delegate credentials will be allowed to vote. They'll vote for a slate of delegates from the county to the state convention, and for the presidential candidate they prefer; state delegates then will be allotted to each candidate in proportion to the presidential preference poll.

Delegate credentials are to be sent out around April 1.

The campaigns are happy with the arrangement because it gives them a way to get votes at the county level that eventually will translate to delegates to the Democratic National Convention.

But some rank and file party activists say they've encountered obstacles to participation in a process that they want to be a part of.

Richard Graham, a 60-year-old carpenter and Clinton delegate, said he found out only a few days ago from the campaign that today was the deadline. He made repeated phone calls and waited for long periods on hold to confirm his registration for the convention.

Graham said he has been participating in county and state Democratic politics for more than 30 years. He wants badly to go to this year's state convention and to run to be elected as a national delegate.

By Tuesday, Graham had cleared up his county convention registration, but he said he was concerned that others without enough time on their hands to be persistent, or who weren't in town during the narrow window before the deadline, might miss out.

"Look what I had to do just to get through by the 19th," he said. "What happens to other people who were delegates to start with who don't get through by then? I'm for Hillary, and Hillary needs every damn delegate she can get her hands on."

Searer said people who miss today's deadline and want to vote at the county convention can contact the campaigns through the state Democratic Party office, where volunteers are manning the phones. The number is (702) 737-8683.

Searer said preparations for the April 12 revote were proceeding smoothly.

"The good news is everyone's been working together," she said. "When we were going through all the paperwork from the caucus, we had a dozen volunteers from each campaign -- people in Clinton shirts and people in Obama shirts sitting next to each other and getting along. So it's actually been pretty heartening."

Contact reporter Molly Ball at mball@reviewjournal.com or (702) 387-2919.