Now Playing: Amber Alert issued for 2-year-old Florida boy

Now Playing: President Trump says nothing about the mistaken missile alert in Hawaii

Now Playing: Senators discuss FBI investigation of claims against Kavanaugh

Now Playing: Trump’s new nationwide presidential alert system being put to the test

Now Playing: Envelope suspected of holding ricin addressed to Trump: Authorities

Now Playing: The Briefing Room: GOP stands firm on Kavanaugh, suspicious packages sent to Pentagon

Now Playing: Hillary Clinton: Kavanaugh’s political ‘revenge’ claim deserves ‘laughter’

Now Playing: Trump’s testy exchange with reporter

Now Playing: Donald Trump Jr. worried about sons in #MeToo era

Now Playing: Trump speaks out on Kavanaugh amid FBI questions

Now Playing: Flake on Kavanaugh’s acrimonious tone: ‘We can’t have this on the court’

Now Playing: FBI investigation into Kavanaugh proceeds on tight deadline

Now Playing: Trump touts trade agreement as FBI investigates Kavanaugh

Now Playing: Melania Trump travels solo to Africa

Now Playing: Trump calls sobriety one of his ‘only good traits’

Now Playing: Senator reacts to scope of Kavanaugh FBI investigation

Now Playing: Kavanaugh’s high school friend interviewed by FBI

Now Playing: Trump blasts Democrats over Kavanaugh investigation

Now Playing: Lawyer: FBI interviewed Kavanaugh friend who allegedly witnessed assault

Now Playing: Trump reverses, says Senate setting rules in Kavanaugh FBI probe