Hatch's campaign manager Dave Hansen said that $10 million tally was everything Hatch had spent since his 2006 election, but acknowledged a big chunk of it was dedicated to winning the nomination.
"Senator Hatch doesn't take any election lightly, but especially this one," Hansen said. "After 2010, we knew this was going to be a tough race. Fortunately, we had the resources to do the things we've needed to do, to be honest with you."
Liljenquist, who has spent more than $600,000, with about $400,000 of that coming from his own pocket, said he feels good about the campaign and has had good feedback from voters since he and Hatch met in their only debate earlier this month.
"We do event after event. We have hundreds of people out knocking on doors. We've put out 100,000 door hangers and 11,000 signs, and you know what? We've done it all through volunteers," Liljenquist said. "It's been awesome. We've blanketed the state. We understand that the way we compete with money is with hard work."
Adam Brown, a political science professor at Brigham Young University, said when an elected official pours money into a race, it's typically a sign that the incumbent is sensing a real threat.
"The fact that you see Orrin Hatch spending a lot shows that he is taking this challenge serious," Brown said. "The flip side is: It's not clear how much spending actually accomplishes. … It's really hard to say that there's any real-world impact."
Outside money • The spending by the Hatch campaign doesn't even paint the full picture, as outside groups and Super PACs (political action committees) have pumped money into the Senate race at an unprecedented rate, and the third-party spending has even trickled down to state and local races.
In the Republican race for attorney general, for example, candidate Sean Reyes has been battered down the stretch by $140,000 in attack ads, dredging up a 20-year-old run-in with kids who egged his car and a campaign-finance complaint in which he was cleared of wrongdoing.
Jason Smith, a Texas lobbyist and former political director for Texas Gov. Rick Perry's presidential campaign, said he created the It's Now Or Never PAC to help get candidates elected who would oppose President Barack Obama's Affordable Care Act. All of the PAC's money has been channeled through a nonprofit to hide the donors, meaning nobody knows who is paying for the ads.
Meantime, Reyes' opponent, John Swallow, the chief deputy attorney general, was also hit by a PAC with Democratic ties, which alleged Swallow was on the verge of being indicted by federal prosecutors for intervening in a contract dispute in Salt Lake County.
State legislative races are not immune from the Super PAC phenomenon, either.
Voters in state Rep. Brad Daw's Orem district have received numerous pieces attacking the incumbent, accusing him of supporting health care reform worse than the Affordable Care Act, being soft on bullying and refusing to vote on immigration.
Those ads have come from a PAC run by Jason Powers, a political consultant who is also working for Swallow. Powers also funnels his money through a nonprofit to conceal donors.
He has sent out similar ads critical of candidates Michael Kennedy, a Utah House candidate who is facing Sarah Nitta in a Republican primary in Alpine.
"The fact is we're going to see more of that until the law changes. The decision [by the Supreme Court to allow unregulated money] was a terrible decision," said Tim Chambless, a political-science professor at the University of Utah. "What we're seeing is more citizens and eligible voters complaining and then not voting. They become angry and feel a little powerless."
More contests • In Salt Lake County, Mark Crockett, a former county councilman, and West Valley City Mayor Mike Winder will square off in what is expected to be a close race for the GOP nomination for county mayor. The winner will face the Democratic nominee, state Sen. Ben McAdams, in November.
In the Republican primary for a countywide council seat, businessman Melvin Nimer will face Joseph Demma, Utah Department of Workforce Services communications boss , to see who will take on incumbent Democrat Jim Bradley this fall.
In one of the few Democratic primaries, voters in the 1st Congressional District will choose between Ryan Combe, a former businessman who now works at Weber State University, and Donna McAleer, a West Point graduate, bobsledder and director of a nonprofit aimed at providing health care for the uninsured.
The Constitution Party will feature a gubernatorial primary between Kirk Pearson and Brandon Nay, both of whom are general contractors.
State Auditor Auston Johnson, who has been in office for 17 years, is facing a challenge from state Rep. John Dougall, R-Highland.
At a more local level, more than two dozen county and school-district races have primaries. And Murray and Weber County school districts have placed large bond questions on the ballot: $65 million in Weber and $35 million in Murray.
Turnout in the primary could be higher than normal. Mark Thomas, administrator of the lieutenant governor's office, which runs state elections, said turnout could reach as high as 25 percent double the traditional primary showing.
"It will likely be higher than past primaries," he said, "because this is the first state primary where we've had a presidential election, as well."
Polls open at 7 a.m. and close at 8 p.m.
There has also been a flood of mail-in ballots, with more than 115,000 sent out and 40,000 returned, plus several counties that haven't even begun to tally the mail-in ballots. Both the Hatch campaign and the Utah Republican Party have aggressively promoted vote-by-mail this election.
Voters can locate their polling places or view sample ballots at the state's election Web site: vote.utah.gov
The Republican primary is open to registered Republicans. Unaffiliated voters can register with the party at their polling places to vote in the GOP contests. Those registered with other parties may not. The Democratic and Constitution party primaries are open to all voters.
Candidates for Tuesday's primary
Hopefuls in top races for Utah's last-in-the-nation primary election Tuesday:
Orrin G. Hatch
Salt Lake County mayor, Republican
Salt Lake County Council, at-large, Republican
U.S. House of Representatives, District 1, Democratic
Attorney general, Republican
State auditor, Republican