Conservative activist Raheem Kassam said Thursday that former Texas congressman Beto O'Rourke (D) is one of the candidates that he fears most going into the 2020 election.

"I've said it for months now, he's actually one of the candidates I fear most," Kassam, who is the global editor-in-chief of right-leaning website Human Events, said during a panel discussion on "Rising."

Kassam predicted that the Democrat not only has the ability to take on President Trump, but also the potential to attract new voters, just like former President Obama did previously.

"He has that aura, he has something that will delineate him on stage from Trump - he's not of the old politics and I think that he can attract new people to vote for him like Obama did," he said.

The conservative, however, noted that O'Rourke also has the most "difficult path" ahead of him compared to other Democratic hopefuls because he doesn't want to swing too far to the left.

O'Rourke on Thursday officially threw his hat into the ring and announced his presidential bid after months of speculation.

The former El Paso congressman first rose to national attention following his closer-than-expected loss to incumbent Sen. Ted Cruz (R) during the 2018 midterm elections.

"This is a defining moment of truth for this country and every single one of us," O'Rourke said during a video announcing his candidacy. "The challenges that we face right now - the interconnected crises in our economy, our democracy and our climate have never been greater."

O'Rourke is heading to Iowa, where he is expected to hold multiple campaign events over the next several days.

Democratic strategist Andrew Feldman emphasized that O'Rourke's chances in 2020 will depend whether he can rekindle the grassroots energy that he unleashed during his Senate run.

"Is he going to be able to raise the 80 plus million dollars off of the same list that he raised in the Senate race - I don't know and if he can't, he's not going to last very long," Feldman told Hill.TV.

-Tess Bonn