Now Playing: Donald Trump Gets More Specific About Policies

Now Playing: GoStream: Carly Fiorina Responds to Donald Trump's Opinion of Her HP Leadership

Now Playing: Political moments that shaped 2018

Now Playing: Trump threatens to 'close Southern Border' if Dems don't fund border wall

Now Playing: Government shutdown continues

Now Playing: 'Deportation bus' politician charged with fraud

Now Playing: Trump gets political on first visit to combat zone

Now Playing: President Trump surprises US troops

Now Playing: Senate returns to work on 6th day of government shutdown

Now Playing: Homeland Security chief reacts to 2nd death of child at border

Now Playing: President and first lady surprise troops in Iraq for Christmas

Now Playing: Trump's surprise visit to troops in Iraq

Now Playing: SPECIAL REPORT: President Trump visits US troops in Iraq on Christmas night

Now Playing: President Trump and first lady Melania visit troops in Iraq

Now Playing: SPECIAL REPORT: President Trump visits U.S. troops in Iraq

Now Playing: Negotiations to end government shutdown at a standstill

Now Playing: Government shutdown showdown continues

Now Playing: Supreme Court Justice Ginsburg discharged from hospital after cancer surgery

Now Playing: Trump asks young girl if she believes in Santa in Christmas phone call

Now Playing: Trump lashes out at Democrats amid government shutdown