State Democratic Party chairman Brian Colón said Monday that he will conduct a full investigation into complaints from Democrats who said they were incorrectly left off the voting rolls and couldn't cast regular ballots in the recent presidential caucus.

Following the Feb. 5 caucus, many voters and some Democratic volunteers who helped run polling places complained to newspapers and radio talk shows that their names weren't on voting lists.

"It has yet to be determined the root cause of the problem," Colón said in an interview Monday. "But we've got to look into it. It's got to be addressed before the June primary."

Voters who weren't on the official list were allowed to cast provisional ballots at the caucus. This contributed to the large number of provisional ballots — about 17,000 statewide — and their counting delayed for nine days the determination of who won the close race in New Mexico between U.S. Sens. Hillary Rodham Clinton and Barack Obama. Last week, Colón announced Clinton was the winner by about 1,700 votes.

An incomplete list of Democratic voters was just one of the problems with the caucus. There was a much bigger turnout than expected, and Colón has admitted the party did not provide enough voting places, which contributed to long lines. Many polling places ran out of regular ballots, which meant voters had to cast provisional ballots; in some cases these were photocopied ballots or blank scraps of paper.

Colón said Monday that he can't yet say anything definite about the magnitude of the voter-list problem because no full analysis of the voting rolls has been done. "Any complaint is worth investigating," he said. "I've gotten enough feedback about this problem that I'm concerned."

Colón said he might have answers about the cause and depth of the problem within about two weeks.

The party got its list of registered Democrats in the state from the Secretary of State's Office. The secretary of state has a contract with a Nebraska-based company called Election Systems & Software to compile state voting rolls. The company also sold the state the paper-ballot tabulators used in state- and county-run elections.

Secretary of State Mary Herrera said at a news conference Monday that the state has contracted with ES&S since 2000 to compile the voter rolls.

Asked Monday whether her office plans to investigate the complaints about the voter lists, Herrera said she hadn't heard any complaints from Colón or other Democratic Party officials.

Asked whether she'd heard some of the problems being reported about people who say their names had been removed from the voter lists, Herrera said, "I'm not hearing any specific problem. I do get a lot of e-mails from people who say my office did a bad job handling the caucus."

The Democratic Party, not the state, ran the caucus.

Herrera said she plans to meet soon with ES&S officials to discuss the June primary.

Paul Stokes, coordinator of United Voters of New Mexico, an election watchdog group, said Monday that he believes "something strange happened" with the voter lists for the caucus, but like Colón, he's not sure exactly what caused it or the magnitude of the problem. He said he's received a couple of dozen or so complaints from people who said their names were incorrectly left off the voter lists.

"It's a confusing situation," he said. "Everything we have is anecdotal. I'm not sure whether the problem was with ES&S or whether there was a problem transcribing the information. There needs to be an investigation. I think the Democratic Party is in the best position to do that."

Contact Steve Terrell at 986-3037 or sterrell@sfnewmexican.com.