By Ashley Killough and Paul Steinhauser
(CNN) -- Sen. Orrin Hatch's political future rests in the hands of 4,000 delegates who will select the party's nominee at Saturday's state Republican convention.
In the last year, the six-term incumbent spent millions of dollars to fend off challenges from candidates and outside groups seeking to drive him out of the Senate - a fate that so far looks unlikely for Hatch.
Hatch, the longest-serving politician in Utah history, needs to win 60% of the delegates voting Saturday in order to secure the nomination and skip directly to November's general election.
If he fails to pass that 60% mark, however, the top two candidates will face off in a June 26 primary.
The senator saw a big turnout in the state's caucuses last month, which elected the delegates to send to the convention. While final numbers have not been finalized, as the delegates are non-binding, state officials said the results looked good for Hatch.
And a new statewide poll of Republicans indicates Hatch could walk out of the convention this weekend as the party's nominee. A Salt Lake Tribune survey released Thursday shows that 62% of Republican voters in Utah back Hatch as the Senate nominee, with 20% favoring former state Sen. Dan Liljenquist, 6% supporting State Rep. Chris Herrod and 12% unsure.
The poll did not ask about seven other lesser-known candidates.
Hatch's re-election campaign released two polls of convention delegates that it conducted, with both indicating Hatch just above the 60% threshhold. Some other surveys conducted by other organizations and campaigns have Hatch below 60%.
Hatch, who was first elected to the Senate in 1976, announced last month that if he's re-elected in November, he won't run again for his seat in 2018.
The senator has a history of reaching across the aisle to work with Democrats, which obviously does not sit well with many tea party activists and other conservatives.
But Hatch has taken steps since the midterm elections to fight that criticism by highlighting his conservative chops, like leading the Senate GOP push for a balanced budget amendment and co-sponsoring a Republican amendment to repeal President Barack Obama's health care law.
Two years ago, the state's boiling tea party movement - largely fueled by the passing of the sweeping health care legislation - ousted longtime Utah Sen. Bob Bennett at the convention when he finished third and the top two candidates faced off in a primary
In the June primary, tea party-backed Mike Lee won the nomination over his opponent, Tim Bridgewater, and ultimately took the seat in the November general election.
But some observers say the political climate in 2012 is different from 2010, with a waning tea party momentum and an incumbent senator more prepared to take on the heat.
The conservative grassroots group FreedomWorks is seeking to replicate its influential role in helping unseat Bennett in 2010, this time, however, with its eye trained on Hatch. A booming voice in the tea party movement, the organization has launched major campaigns targeting incumbents in races across the country.
In Utah alone, its super PAC FreedomWorks for America, has spent more than $600,000 in ads and aggressive grassroots efforts to dismount Hatch, arguing the six-term senator has held his position for far too long.
While it was successful two years ago, the group acknowledged the environment is more challenging this time around, especially after Hatch's strong turnout in the caucuses.
"The battle has definitely gotten more difficult, that's for sure," Russ Walker, the super PAC's national political director said. "If we had the same delegation in 2012 as 2010, there'd be no question in anybody's mind, Hatch would be done."
But Walker still maintains Hatch will fail in his endeavor to pass the 60% threshold on Saturday, and the race will be settled in a primary.
"This guy had to spend over $5 million just to survive the caucus," Walker said. "For a state representative of 36 years, that demonstrates a severe weakness."
Like other high-profile races, the Utah Senate race has seen its fair share of spending from outside groups, including FreedomWorks.
Evelyn Call, Hatch's communications director, criticized the group, saying it repeatedly launched misleading ads about Hatch and ran an overly negative campaigns.
"They tried to make it become a race between Senator Hatch and FreedomWorks," Call said. "Instead of highlighting our own record, we had to spend a lot of time on half-truths and lies, and in some degree, that cost us more money."
But Hatch's campaign saw support from at least five outside groups, including the super PAC Freedom Path and the National Rifle Association. In total, those groups outspent FreedomWorks in the lead-up to the state's caucuses last month.
After the caucuses, the state saw a noticeable drop in ads and attacks from the outside groups, as the focus shifted to the 4,000 delegates set to vote at the convention, rather than the population at large.
A spokeswoman for Liljenquist, the former state senator who represents the largest threat to Hatch, said she was glad to see the groups scale back, arguing that the big-money noise was drowning out the candidates' voices.
"They're actually letting the candidates run their own races now, and I appreciate that," Holly Richardson said. "It's our opportunity for Dan to get his message to people one-on-one."
While the former state senator did not have a super PAC explicitly backing his campaign, FreedomWorks expressed its support for the candidate early on. But as a bitter fight ensued between the third-party groups, Liljenquist told the Salt Lake City Tribune last month that he wished they would just "get out of the way."
And the downsizing of outside activity between the caucuses and Saturday's convention - might have changed the dynamics of the race, a state Republican official told CNN.
Without independent parties weighing in so heavily, the candidates themselves have more room to meet with the delegates individually, the official added.
"This is the ultimate time in retail politics," said the official, who did not have authorization to go on the record. The source added that with candidates only courting the votes of 4,000 delegates now, television and radio ads are "just completely unnecessary."
"The only thing that counts is the candidates getting in front of delegates, either individually or at home," the source said. "The need for big money has just decreased so much."