A Republican political consultant said he and others are still investigating a mysterious robocall received on Election Day that encouraged GOP party members to skip voting because the presidential race was all but decided.

Tim Clark, who worked with 10th Assembly District candidate Jack Sieglock and others, said that while the call didn't mention any local candidates, it appeared to be directed at Republican voters in contested state legislative districts.

So far, he said, there are reports of the calls being received in ADs 10, 15 and 78, as well as state Senate District 19.

"The fact is, this tactic wasn't about a contrast in candidates, wasn't about issues," he said. "It was purely about suppressing Republican voters."

Clark said the calls were made by an unknown group at a phone bank at about 5:30 p.m. Tuesday, around the time the national electoral vote for the presidency began to swing decidedly in the direction of Democrat Barack Obama, but still well before polls closed in California at 8 p.m.

The call identified itself as a "breaking news alert" that said Obama was likely to win the presidency, and also said Democrats would maintain a large majority in Congress regardless of how votes turned out in Colorado and California.

Neither who made the call nor who paid for it were part of the message. Robocalls of such a nature are illegal under California utilities law, though rarely prosecuted.

Clark said it was hard to gauge whether the call convinced many voters to stay home, or how many phones received it. He said that in Assembly District 10 alone, however, the call could've gone out to as many as 35,000 registered Republicans who hadn't cast a ballot before Election Day.

"It's one of the worst last-minute dirty tricks I've seen in my 15 years in this kind of work, and I've seen a lot," said Clark, who is based in Sacramento.

He said he believed the call came from a group that was supportive of Democratic candidates, and he noted that labor unions were active in all of the legislative districts were the calls were received.

Clark said Republicans could bring a complaint against whoever made the calls under civil rights law for willful attempts to suppress votes.

Roman Porter, executive director of the state Fair Political Practices Commission, said the only violation his office would investigate would be if the robocalls lacked a disclaimer and specifically targeted a state legislative candidate or ballot measure.

"You have to have express advocacy for a candidate or ballot measure," he said. The Tuesday robocall appears to lack that marker, he said.

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