Sen. Toomey told KDKA his vote to convict Trump over his role on January 6 "was not a close call."
"I have absolutely no doubt that ... Trump intended to thwart the outcome of the election," he said.
Toomey is stepping down after 12 years in the Senate and will be succeeded by John Fetterman.
Retiring GOP Sen. Pat Toomey of Pennsylvania in a recent interview said his vote to convict former President Donald Trump for "incitement of insurrection" for his role on January 6, 2021, was "not a close call," with the lawmaker stating that he believed the commander-in-chief "intended to thwart the outcome of the election."
While speaking with political editor Jon Delano at KDKA, the Pittsburgh-area CBS affiliate, Toomey remarked that he felt Trump's narrow loss to now-President Joe Biden in Pennsylvania in the 2020 election played in a critical part in his approach to seeking to overturn the results.
"On Jan. 6, the reason why he didn't want to intervene and call off the mob was because he wanted to delay the process of certifying the election because he thought at the time he was fairly close to persuading the legislature of Pennsylvania and several other states to pass legislation creating a new slate of electors who would vote for him," Toomey said.
The conservative lawmaker, who served in the House from 1999 to 2005 before winning Senate races in 2010 and 2016., was one of seven Republicans who voted to convict Trump during his second impeachment trial in February 2021. (Trump was eventually acquitted, as the 57-43 vote fell short of the two-thirds majority needed for a conviction.)
"For me, it was not a close call," Toomey said of the vote. "I have absolutely no doubt that President Trump intended to thwart the outcome of the election."
When Toomey was asked if he had any regrets about the vote, the lawmaker was resolute in his thinking.
"That's just beyond outrageous ... That is as an egregious offense to the Constitution as I can think of - to knowingly thwart the outcome of an election so you can stay in power. And I think that's exactly what happened there," he said.
"I felt like I had no choice," he continued to say. "If that's not an impeachable offense, then I'd have a hard time thinking of what is."
But when asked if Trump should be tried criminally for his role, Toomey said the picture was more unclear in his eyes.
"I just don't know enough about the facts and circumstances," he said. "We've seen special counsels run amok before so I'm not enthusiastic about this," he added, alluding to Attorney General Merrick Garland's decision to appoint a special counsel to handle any criminal probes involving the former president.
Toomey, who chose not to run for reelection this fall, will be succeeded in January by Democratic Sen.-elect John Fetterman.