Democratic presidential candidate Sen. Bernie Sanders has amassed a giant following in the wake of his successful grassroots campaign. He’s gained so much momentum that he’s now perceived as the new Democratic frontrunner, surpassing opponent Hillary Clinton.

Here are three reasons from The Hill that explains why he’s the new frontrunner.

1. Within a surprisingly short time period, increased name recognition and an energized base of Democratic voters have allowed Sanders to compete and even surpass Clinton in various polls.

2. Clinton can’t win the Democratic nomination or presidency with the FBI as a running mate.

3. Classified information has already been found within Clinton’s emails and there’s a great likelihood of more revelations pertaining to breaches in protocol. As a result, the servers and emails (of other people) linked to Clinton’s correspondence can also become part of this ongoing saga.