No, it's not. When people try to "drain the swamp", several things push them to become authoritarians, even if they weren't before.

1. The definition of "the swamp" drifts from "open, blatant corruption" towards "everyone who opposes me". That's a much larger set, so you need bigger guns.

2. Some people agree that "the swamp needs drained", but disagree on what "the swamp" is, and/or disagree on how to drain it.

3. People don't agree with everything you're doing. (Maybe this is the same as #1 and/or #2.) Some people oppose you because they're corrupt, some people oppose you because they dislike change, and some people oppose you because they dislike your methods. The more force you use, the more people oppose your methods. But as opposition grows, you need more force to get anywhere.

The result is that anybody who sets out to do something like "drain the swamp", if they stick with it as an objective, gets pushed toward more and more authoritarianism to try to make it happen.

Look, Bernie isn't Trump. He's been consistently pushing in the same direction for decades. He actually cares about his issues; he's not just using them as a cover for seeking power. But I think that, if he got actual power (president, not just senator), the dynamics of the situation would also push him to become more and more authoritarian.

(Would he become equivalent to Trump? Hopefully not.)