White House counselor Kellyanne Conway said on Wednesday that Democrats are scrambling to kill off the presidential campaign of Sen. Bernie Sanders, I-Vt. because he’s too popular for the party’s own good.

“The Democrats seem really desperate to find an alternative to Bernie Sanders,” Conway said on Fox News. “He’s the clear, announced front-runner right now, in the polling and on the ground.”

Conway was asked about an impending announcement from former Vice President Joe Biden, who is expected to declare a run for the Democratic presidential nomination on Thursday.

She said Biden represents a more mainstream voice to which Sanders is the antithesis. This, she said, scares Democratic Party leadership.

“Bernie Sanders has a lot in common with Donald Trump,” Conway added. “Which is he doesn’t really care what his party thinks about his candidacy, at this point in the primaries, he’s connecting directly with the voters and raising small dollar amounts.”

Bernie has polled well in the early going of the 2020 Democratic primary. According to a RealClearPolitics average of polls, he trails only Biden.

South Bend, Ind., Mayor Pete Buttigieg, also a 2020 candidate, told the New York Times he doubted the resolve of Sanders’ coalition and said the self-described democratic socialist lacked the novelty he possessed in 2016.

Sanders was surprisingly competitive in the 2016 primary, and emails stolen from the Democratic National Committee and published by WikiLeaks showed that some officials sought to tilt the contest in favor of Hillary Clinton. Although Clinton won the nomination and Sanders went on to support her candidacy, members of his base were resentful.

This time around, the issue of general election defectors remains a factor.

A so-called “Bernie or Bust” wing of Sanders’ base claims they’ll switch over after the primary election should Sanders lose and vote for Trump in 2020, like 12% of them did in 2016. A new Emerson College poll revealed that even more could be susceptible to voting for Trump instead of a similar left-wing candidate to Sanders.

“The only difference between Bernie Sanders and Donald Trump,” Conway said. “ ... is that Bernie Sanders’ ideas are terrible for America.”

[Read more: Bernie Sanders internal polling shows Trump losing 3 states key to 2016 win]