"They really want to damage me so I can no longer go back to work for you, but I don't think that's going to happen," Trump said to chants of "four more years" at think tank policy summit.
Several months ago, the company began cracking down on pages related to the popular conspiracy theory
Sgt. Daniel Perry could face life in prison.
The Republican lawmaker went on to accuse major brands and the political left of attempting to minimize the event.
"The FBI is fighting a fire of racist violence and with words like that [the] president is using a firehose to spray gasoline on that fire," Comey said.
"We must examine the forces of domestic extremism that span the ideological spectrum," Grassley said.
A group of Trump supporters boxed in a Biden bus in Texas on Friday.
Romney did not vote for Trump during the 2016 election either.
Federal officials are investigating two incidents in north Texas after two ICE field offices received envelopes with white powdery substances this week.
Judge stops Federal prosecutors from banning alleged "left-wing activist" from Twitter and Facebook