"As Abraham Lincoln said, a house divided against itself cannot stand," the Louisiana Republican said on CNN's "State of the Union." "Our nation, our conservative movement, our Republican Party can't stand if we are divided against ourselves. So, at some point, we have to come together for all those reasons."
"Obviously, he is the president-elect. He has 270 Electoral College votes," Cassidy said. "As we're a nation of laws, and this is the Constitution, and this is the law, and this is how it breaks out, and the courts have ruled, then President Biden's going to be our next president."
Cassidy added that "clearly, there's still disappointment," in Trump's loss, but "in terms of the functional aspect of actually beginning the transition, that has begun" for Biden to take over the presidency on Jan. 20.