"Threats should be taken seriously and our laws should be enforced to ensure accountability," a spokesperson for the Republican senator said.
"It's shocking. We can have differing points of view. We can express them without degrading one another, without denigrating one another," Murkowski said.
The endorsement came after former President Donald Trump backed Tshibaka last month in an effort to oust all the Republicans who voted for his impeachment.
"Murkowski has got to go! Kelly Tshibaka is the candidate who can beat Murkowski—and she will," Trump said in a statement Friday.
The Alaska senator is one of three Republicans set to support the probe into the storming of the U.S. Capitol.
"You know, usually I'm staying in the background and I just couldn't, I couldn't stay quiet anymore," Gladys Sicknick told reporters
The GOP congressman said it's an "easy" choice not to support Trump if he becomes the Republican Party's 2024 nominee.
"Republicans that say they're for [Obamacare], we gotta keep them honest, and you gotta send home the ones that lie to you," the Republican senator said.
This weekend, Trump and a number of high-profile GOP lawmakers and supporters are meeting for a Republican National Committee donor retreat in Palm Beach, Florida.
Murkowski was one of seven GOP senators who voted to convict the former president during February's impeachment trial.
"The party does not want Lisa Murkowski to be a Republican candidate," said Tuckerman Babcock, who also works on the GOP State Central Committee.
The Alaska senator was one of seven Republicans in the Senate who voted to convict former President Donald Trump during his February impeachment trial.
The Alaska Republican called the bill "wholly partisan" and dismissed "unnecessary" measures in the package.
The Wyoming Republican praised Murkowski on Sunday after Trump called her "disloyal" and "very bad" and promised to campaign against her in Alaska next year.
The Alaska senator is the 86th most popular Republican in Congress, with 13 percent sharing a positive opinion and 23 percent sharing a negative opinion of her, according to YouGov.
"It now seems clear that there is no path forward to gain confirmation, and I do not want continued consideration of my nomination to be a distraction from your other priorities," Tanden wrote.
The former president listed every Republican who voted to impeach him and demanded to "get rid of them all."
So far, five of the seven Republican senators who voted to convict former President Donald Trump during his second impeachment trial have faced censures from local or state GOP groups.
Some of the Republican senators who voted to convict former President Donald Trump at his impeachment trial faced censure from local GOP groups in their states.
Susan Collins of Maine said Trump created a "dangerous situation" and put his "selfish interest" over the interests of the country.
Some Republicans are calling for the GOP senator, who doesn't plan to run in 2022, to be formally censured.
The Maine Republican senator said the former president had subordinated "the interests of the country to his own selfish interests."
In September, the former Alaska governor threatened to unseat Murkowski in the 2022 elections if she went "rogue" again.
Senators Susan Collins, Mitt Romney, Lisa Murkowski, Ben Sasse, Patrick Toomey, Bill Cassidy and Richard Burr joined all of their Democratic colleagues to vote for a conviction on Saturday.
"I just don't see how Donald Trump will be reelected to the presidency again," Sen. Lisa Murkowski (R-Alaska) told reporters during the second day of former President Donald Trump's second Senate impeachment trial.
The Alaska senator has said the party is more than the former president, as the Republican lawmakers who voted for impeachment insist they have no regrets.
The poll, which tallied responses from voters in Maine, West Virginia, Alaska, and Arizona, is a warning to Republican senators to listen to their constituents, WorkMoney CEO Carrie Joy Grimes told Newsweek, noting that her group is nonpartisan but "we know what time it is."
Former Trump administration officials have publicly said the president plans to run again in 2024.
"We recognize your calls for unity and want to work in good faith with your Administration," the GOP senators wrote Sunday.