The presumptive GOP presidential nominee faces Republican challengers Ron Paul and Fred Karger in Tuesday's election.
Romney, a Mormon and graduate of Brigham Young University who oversaw the 2002 Winter Olympics in Salt Lake City, is a hugely popular figure in Utah, where more than 60 percent of residents are members of The Church of Jesus Christ of Latter-day Saints.
Romney won 90 percent of the vote in Utah's 2008 presidential primary.
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