Herrod said it wasn't so clear cut.
"It's one of the options," Herrod said. "I'm not ready to say yes, but to say I'm not looking at it wouldn't be honest."
He said he had a long conversation with his wife about the potential Senate race on Monday evening but he said he wants to keep all of his options open until the Legislature finishes re-drawing congressional boundaries a decision postponed until later this month.
And Sandstrom acknowledged he has asked his colleagues not to commit to supporting candidates in the race for Utah's new 4th Congressional District because he might decide to run there.
Sandstrom had planned to run in the 3rd Congressional District, but when Congressman Jason Chaffetz surprised colleagues by announcing he would seek reelection, Sandstrom filed to run for the 2nd Congressional District seat now held by Democratic Rep. Jim Matheson. Sandstrom said Wednesday that it would be easy to switch his sights to the new 4th Congressional District.
The Orem lawmaker said he is flying to Washington, D.C., Monday to meet with the National Republican Congressional Committee to talk with leaders and supporters there about a run.
"I did not imagine until last week I'd make a run in the 4th," Sandstrom said. "But with the way the maps are drawn, I think a lot of people would have to look at the 4th."
He also said he's already looked into moving his residency so he'd actually reside in the 4th Congressional District if he went that route. The Legislature won't settle on that district's boundary until later in the month, but Sandstrom said the likely map versions show the boundary about three houses away. Sandstrom said it would be important to him to live in the district he represents.
If Sandstrom decides to get in that race, it would pit him against Rep. Carl Wimmer, a fellow co-founder of the Patrick Henry Caucus. That group of legislators is focused on states rights issues.
"I would be extremely surprised if Sandstrom made a decision to run against me," Wimmer, R-Herriman, said. "He has pledged not to on numerous occasions. We are very close friends, and frankly I trust my friend. There's just no way."
Saratoga Springs' Mia Love has also said she is exploring a bid for the GOP nomination in the 4th District.
Both Herrod and Sandstrom were outspoken opponents of the guest-worker immigration law the Legislature passed last session, which would enable undocumented immigrants to pay a fee, pass a background check and receive a Utah-specific work permit, allowing them to work legally in the state even if they are not citizens. It was written with a trigger date of July 1, 2013, and state officials have been working since it was signed by Gov. Gary Herbert in March to obtain a federal waiver to allow it to work as a pilot program.
Hatch has angered many tea party activists and devout Republicans who believe the six-term senator has been in office too long and is not conservative enough. National groups like Freedomworks have made him a target in the upcoming election.
But Hatch has raised millions and made efforts to reach out to the conservative wing of his party, fearing he might become the next Bob Bennett, a three-term senator who lost his re-election bid in 2010 amid a tea party uprising.
"It's a free country. He can run if he wants to," said Hatch's campaign manager, Dave Hansen, of Herrod's apparent decision to challenge the senator. "We're confident the senator is going to have the support to win re-election."
State Sen. Dan Liljenquist is still weighing whether he will run against Hatch.
"I have not made a final decision," the Bountiful Republican said. "My wife and I are going to take until the end of November to decide what we're going to do."
Liljenquist, who has six children under the age of 11, has said he has to decide whether the campaign would be right for his family.
Tea party co-founder David Kirkham, who has said he might run for either the Senate or governor, said Tuesday he hasn't made up his mind yet and likely won't for several more weeks.
David Montero contributed to this report.