Republican Senator Josh Hawley has been accused of "having blood on his hands" and dubbed "one of the most despised men in America" by Fox News following the extraordinary attack on the US Capitol.
Along with more than 140 congressional Republicans, Mr Hawley voted to overturn the election result - even after a violent mob descended on the Congress building in Washington.
Mr Hawley now faces calls to resign, has lost major donors, a book deal and isolated many of his political supporters.
So who exactly is the young senator?
The 41-year-old conservative was elected as Missouri's junior senator in 2018 and is a fierce supporter of President Donald Trump.
The youngest member of the US Senate, Mr Hawley was born in Springdale, Arkansas, to a banker and a teacher, and later moved to Lexington, Missouri in 1981.
He graduated from Stanford University with a Bachelor of Arts in 2002 and Yale Law School in 2006 and is well-known for his political ambitions.
Josh Hawley (L) looks on in the House Chamber during a reconvening of a joint session of Congress on January 06, 2021. Source: Getty
As Missouri's attorney-general, Mr Hawley initiated several high-profile lawsuits - including one against the Affordable Care Act and an investigation into companies associated with the opioid epidemic.
In 2018, Mr Hawley - encouraged by Vice President Mike Pence - was elected on the back of a Senate campaign championing Mr Trump's agenda.
During his time as Senator, he's spoken out against Big Tech, called China a "police state" and voiced support for Hong Kong protests.
Long seen by many as a rising star in the Republican ranks, Mr Hawley is now facing an avalanche of criticism following his role inciting the attempted Washington insurrection.
The Senator's role in the siege on The Capitol
As he walked into the Capitol on Wednesday, Mr Hawley cheered on pro-Trump protesters gathering outside the building with a thumbs up and fist pump.
Despite there being no evidence of widespread electoral fraud, on 6 January Mr Hawley asked his colleagues “to address the concerns of so many millions of Americans” by investigating the 2020 vote.
"Violence is not how you achieve change," a clearly shaken Mr Hawley said later that night on the Senate floor after police expelled the intruders and secured the building.
He faced instant rebuke from Republican Senator Mitt Romney, who blasted those who objected to finalising President-elect Joe Biden’s election.
Senator Josh Hawley on Wednesday, as the crowd that would storm the Capitol marched. Source: AP
“Those who choose to continue to support his dangerous gambit by objecting to the results of a legitimate democratic election will forever be seen as being complicit in an unprecedented attack against our democracy,” Mr Romney said.
“That will be their legacy,” he added.
Jack Danforth, a former US Senator and an early ally of Mr Hawley, went as far to say that supporting him was "the worst mistake he's ever made in his life."
Senator Joe Manchin told CNN that Ted Cruz and Josh Hawley, who both challenged the Electoral College have "blood on their conscience" after five people died either during the insurrection, or in its aftermath.
President-elect Joe Biden echoed the sentiment, claiming Mr Hawley and Mr Cruz were “just as responsible” as Mr Trump for the violence.
It had been assumed in political circles that Mr Hawley would run for president in 2024. But his unfaltering support for Mr Trump would appear to have dealt his political ambitions a fatal blow.
Hallmark has demanded that Mr Hawley, along with Republican Senator Roger Marshall, return all campaign donations after they challenged the Electoral College.
"Hallmark believes the peaceful transition of power is part of the bedrock of our democratic system, and we abhor violence of any kind," Hallmark spokesperson JiaoJiao Shen said in a statement.
Mr Hawley's publisher, Simon & Schuster, also cancelled his book deal in the wake of last week's violent insurrection on Capitol Hill, citing "his role in what became a dangerous threat to our democracy."
Mr Hawley said the publisher had caved to a "woke mob" and claimed the scrapping of his book deal was a "direct assault on the First Amendment."
Meanwhile, thousands of students from the bar association at the University of Missouri law school, where Mr Hawley taught, have also issued a statement calling for his resignation.
Mr Hawley sent out a fundraising email after Congress had begun its joint session to count the Electoral College results, asking for US voters to donate and claiming he will not bow down "to career politicians in Washington".
Former Missouri Secretary of State Jason Kander heavily criticised Mr Hawley on Twitter.
“You chose something as trivial as your political ambition over our country. Disgusting. Absolutely disgusting, Senator. I can’t even imagine entertaining such a choice, let alone making it. What kind of an American does something like this?” he said.
Additional reporting by AP
