SALT LAKE CITY — Tuesday will be 2010's first election day, when Utahns will gather in neighborhood caucuses to elect delegates to party conventions.

It is a particularly important day for three-term Sen. Bob Bennett, R-Utah, and the seven conservatives who are challenging him from the right. They report frenetic efforts to ensure their supporters attend the caucuses and are elected. Democrats also have two candidates in that Senate race.

Other races where parties must use the caucus, convention and primary process to narrow the field include the 2nd District U.S. House race where Rep. Jim Matheson, D-Utah, faces a challenge from the left in his party while multiple Republicans also are running; the GOP gubernatorial race; and numerous legislative and county races.

In the GOP Senate race, Bennett has consistently said the greatest threat to his re-election is at the state GOP convention, where delegates tend to be more conservative than the general public. He figures if he can survive the convention, he will do well with voters in primary or general elections.

For example, he had about $800,000 in cash at the end of 2009, or more than twice all his competitors had combined. That could help him more easily afford the TV ads and billboards needed for a primary.

But his challengers — entrepreneur Tim Bridgewater, former congressman Merrill Cook, businesswoman Cherilyn Eagar and attorney Mike Lee, plus just-filed candidates David Chiu, Leonard Fabiano and Jeremy Friedbaum — know it doesn't take much money to get friends and family to caucuses, nor much to campaign to relatively small numbers of delegates before the convention.

At the convention, if any candidate receives 60 percent of the vote they become the party's nominee and advance to the general election. Otherwise, the top two candidates face off in a primary election.

The first step comes Tuesday with the election of delegates at the caucuses.

"We have 5,000 people pledged to run as delegates of Bob Bennett," said Jim Bennett, the senator's son and campaign manager. To demonstrate how many that is, the state GOP convention two years ago had only 3,777 delegates.

Jim Bennett said most of those people signed up online, and many have attended meetings with the senator — and received information packets about how to run.

Lee and Eagar also are optimistically predicting they could earn 60 percent and take the nomination outright at the GOP convention if all the people they are expecting to run as delegates are actually elected.

"We've got a lot of people who have committed," Lee said, while not giving a specific number. "We also have another 600 people who have signed up as volunteers, who will be helping with efforts to get out the vote, put up signs, pass out literature and make calls to get more people to sign up."

Steve Roah, communications director for Eagar, also said that campaign is optimistic it can achieve 60 percent of convention votes because Eagar and other campaign officials "are out every single day pounding the phones with past delegates" seeking support. "We're doing this as a grassroots campaign, without spending a lot of money."

Among others, Cook said he has "been in a whirlwind since we announced just three weeks ago." He said he's tried to meet as many past delegates as possible.

"We reached over 1,000 by personal telephone calls already and into the hundreds in small library meetings we've held" in several counties. He adds he will have volunteers at caucuses passing out literature and information.

Bridgewater noted that he has visited all 29 counties, at least twice, to help seek delegates in all corners of the state. He said he has talked to or sent mailers to all past delegates.

"I think a large portion of delegates who are elected on Tuesday will be undecided, but we should have a large chunk of Bridgewater supporters who get elected as well," he said.

To vote at Republican caucuses, participants must be registered to vote as Republicans. "But they can register at the caucuses if they like," said Party Chairman Dave Hansen.

Democratic caucuses are open to anyone of any party. "We don't require a loyalty oath," said Todd Taylor, executive director of the Utah Democratic Party.

To find your local caucus site, go to www.utgop.org for Republicans and www.utdemocrats.org for Democrats.

e-mail: lee@desnews.com