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A longtime aide to Sen. Bernie Sanders (I-Vt.) said during an interview that aired on Thursday that the Vermont senator would continue to take on the political establishment if he is elected president in 2020.

"This is something really important as we think about a Bernie Sanders presidency," David Sirota, an adviser and speechwriter for Sanders's 2020 campaign, told Hill.TV. "Bernie Sanders is under no illusion that if you defeat the establishment in an initial election that the establishment will simply melt away and go away."

"Bernie Sanders, through his own experience, has understood and known how to deal with how to combat that establishment once you are in power," he added.

Sirota, who previously worked for Sanders when the senator was a member of the House, pointed to Sanders's time as the mayor of Burlington, Vt., from 1981 to 1989, saying the local establishment tried to stymie the then-mayor at every turn. In response, Sirota said, Sanders backed a series of local candidates to try and win back some power for his agenda on the city council.

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"When Bernie Sanders says I am going to go to other states, I am going to into districts of members of Congress who are opposing our agenda and I'm going to campaign for our agenda to put popular pressure on those members of Congress — that is the experience Bernie Sanders had as mayor and that he's had really for his whole political career," he said.

Sirota's comments come just a week after Sanders, along with six other 2020 contenders, took the debate stage in Los Angeles. The event marked the sixth and final Democratic presidential debate of 2019.

A day after the debate, the Sanders campaign announced that it has raised more than $1 million. Sanders, a staunch progressive, has avoided wealthy donors and raked in $25 million in the year's third quarter.

Though Sanders continues to be one of the primary field's most effective fundraisers, he still trails former Vice President Joe Biden by a sizable margin in most national polls.

According to a Morning Consult survey released Monday, Biden continues to lead the pack with 31 percent for the second week in a row, while Sanders placed second with 21 percent support.