-
Now Playing: Trump Doubles Down on Criticism of Khan Family as Blowback Continues
-
Now Playing: Donald Trump Feuds With Parents of Fallen US Soldier
-
Now Playing: Khan Family Says Trump Has 'Black Soul' After Trump's Comments
-
Now Playing: President Trump spends last weekend in the White House
-
Now Playing: Washington, DC preps for Biden inauguration
-
Now Playing: Biden introduces Dr. Maria Zuber
-
Now Playing: Biden introduces Dr. Frances H. Arnold
-
Now Playing: Members of Congress concerned for safety
-
Now Playing: Trump plans to leave White House with 'military-like feel'
-
Now Playing: Washington readies for inauguration as security concerns remain high
-
Now Playing: Inauguration security ramps up, over 300 people face charges in Capitol riot: Part 2
-
Now Playing: DC police officers recount violence, lawmakers demand Capitol security probe: Part 1
-
Now Playing: FBI prepares for Inauguration Day, institutes security lockdowns
-
Now Playing: Biden promises to deliver 100 million shots of vaccine in 1st 100 days
-
Now Playing: Trump plans military-style send-off for himself on Inauguration Day
-
Now Playing: Every social media site that restricted Trump or banned from app stores since Jan. 6
-
Now Playing: Biden announces 5-point COVID response plan
-
Now Playing: Breaking down the future of the Republican Party
-
Now Playing: How Joe Biden's inauguration will be different from previous years
-
Now Playing: Inaugural addresses through the years