Mike Pence continued drawing a line in the sand - of sorts - against Donald Trump's push to overturn their 2020 election loss, saying Thursday "there's almost no idea more un-American" than the idea of one person choosing the president over the voters. Trump, 75, infamously refused to accept their defeat last November and launched months of media campaigns and fraught legal efforts to fight the loss. Then, on Jan. 6, Trump gave a disgruntled speech to his supporters outside the White House calling on them to march on Congress and calling on Pence, 62, to somehow take over the joint congressional session and block the certification of President Joe Biden and Vice President Kamala Harris' victory. In a statement hours before the deadly attack at the U.S. Capitol that day, which briefly delayed the session and sent lawmakers into hiding, Pence explained he had no authority to try and overturn the votes. In a speech Thursday at the Ronald Reagan Presidential Library in Simi Valley, California - and without mentioning Trump by name - Pence said he'll "always be proud" of what he did on Jan. 6, when he and lawmakers from both sides of the aisle returned to the Capitol later that night to certify the results. Pence called Jan. 6 "a dark day in the history of the United States Capitol" and lamented "there are those in our party who believe" he could have single-handedly blocked the final counting of the Electoral College votes that day. "The Constitution affords the vice president no authority to reject or return electoral votes submitted to the Congress by the states," Pence said. "Truth is, there is almost no idea more un-American than the notion that any one person could choose the American president," the former vice president said.