What happens if neither presidential candidate gets 270 electoral college votes?

What would happen if neither Vice President Kamala Harris or former President Donald Trump get the 270 electoral college votes that it takes to become the president? In that case, according to the 12th Amendment, the House would decide the president and the Senate would choose the VP. This has only happened once before. Casey Burgat, an assistant professor at the George Washington University Graduate School of Political Management talks about the possibility of this outcome.