(CNN) - Voters will head to the polls in Utah Tuesday, where a Republican Senate nomination battle is grabbing the spotlight.
The contest will be another test of the political strength of the Tea Party Express. The national Tea Party group, which is based in California, is backing and assisting lawyer Mike Lee in the battle to succeed fellow Republican Bob Bennett, who is supporting the other candidate on the ballot, businessman Tim Bridgewater.
Bridgewater and Lee finished first and second last month at the Utah Republican party convention, advancing to the June 22 primary. Bridgewater and Lee touted themselves as more reliable conservatives than Bennett, who finished third in the voting by delegates, eliminating him from advancing to the primary and ending his chances of re-election for a fourth term in the Senate. Bennett became the first sitting senator to go down in defeat in a primary season marked by a strong anti-incumbent sentiment.
Tea Party Express, best known for its three national bus tours, is running radio ads supporting Lee. The group recently pumped more than half a million dollars into the recent fight for the Republican Senate nomination in neighboring Nevada, helping transform former state lawmaker Sharron Angle, once a long-shot, into an easy winner in this month's primary election.
FreedomWorks has also endorsed Lee, and its volunteers are assisting in get out the vote efforts on the ground in Utah. FreedomWorks is a nonprofit conservative organization that helps train volunteer activists and has provided much of the organizational heft behind the Tea Party movement.
But the contest appears to be dividing Tea Party activists, as the leader of a local Tea Party group in Utah backed Bridgewater on the day before the primary.
Bennett upset many conservatives with his vote in 2007 in favor of President George W. Bush's plan for a pathway to citizenship for some illegal immigrants, and his 2008 vote in favor of the federal bailout of large banks and financial institutions. The fiscally conservative Club for Growth actively worked to defeat Bennett, as did local Tea Party organizations and Tea Party Express. The GOP dominates statewide elections in Utah and the winner of the Republican primary will be considered the overwhelming favorite to win the general election in November.
A non-partisan Salt Lake Deseret News/KSL poll conducted last week by Dan Jones and Associates indicated Bridgewater leading Lee by nine points, with a very high one in four likely GOP primary voters undecided.
–Follow Paul Steinhauser on Twitter: @psteinhausercnn