When Trump announced the news, the crowd began to chant "Lock her up!"
"They are reopening the case into her criminal and illegal conduct that threatens the security of the United States of America," Trump said, though the FBI did not specifically say it was re-opening the case, but that they will "take appropriate investigative steps" and review the newly discovered emails.
"Hillary Clinton’s corruption is on a scale we have never seen before. We must not let her take her criminal scheme into the Oval Office. I have great respect for the fact that the FBI and the Department of Justice are now willing to have the courage to right the horrible mistake that they made."
Trump later returned to the subject and declared that the FBI's announcement is "bigger than Watergate."
"Real change also means getting rid of the corruption in Washington and again, maybe be that’s happening, wow. It’s a big day. Think of it. I won my first primary in New Hampshire, and I am getting here, and the news this morning is, this is bigger than Watergate," Trump said. "This is bigger than Watergate in my opinion. This is bigger than Watergate."
"Hillary bleached and deleted 33,000 emails after receiving a congressional subpeona. That alone to me, there were more serious things done. But how does it get much more? But that was so — that was so obvious," he continued.
He then suggested that the FBI's decision to review new emails from Clinton's server also rights another action that Trump has claimed shows corruption among Democrats — Virginia Gov. Terry McAuliffe's (D) donation to the wife of an FBI official who later worked on the Clinton email investigation.
"Maybe now that takes care of itself. Right now that takes care of itself I think," Trump said. "I think. Very proud that the FBI was willing to do this, actually, really."
Correction: Due to an editing error, the original version of this story reported that the new emails were from Clinton's private server, which goes beyond what Comey's letter states. Reporting that has come out since has suggested that emails from Clinton's private email server were found on devices owned by Anthony Weiner and Human Abedin seized by the FBI.