I agree with everything Nathan Gonzales writes in this Roll Call piece, including the following passage:

If Joe Biden wins the White House, and particularly if they also gain control of the Senate and expand their majority in the House, Democrats will be tempted to (and progressives will likely) claim a mandate. They might believe that voters love them and all the liberal policies they’ve been talking about lately.

In reality, Democratic victories this fall will likely happen because enough voters are fed up with Trump’s first four years in office and are tired of Republicans making excuses for him or ignoring his most polarizing actions.

That means if Democrats in Washington next year push forward with legislation akin to the Green New Deal or a single-payer health care system, they risk a backlash from voters who never wanted the party (or the country) to go that far to the left. They had just reached their limit with Trump. And that means Republicans would have an opportunity to immediately rebound in the 2022 midterms.

Democrats don’t enjoy getting slaughtered in the first midterm after they succeed in winning the presidency, but it’s happened consistently going back all the way to 1966. You can say this demonstrates a refusal to learn, but it’s really more about getting shit done when you have the power to accomplish it. Lyndon Johnson’s Great Society legislation was made possible by ginormous majorities the party won in the 1964 election. Perhaps some of it could be considered overreach, but the number one priority wasn’t maintaining their numbers in Congress. There was civil rights legislation to pass and a war on poverty to wage.

Carter and Clinton also experienced a backlash that was at least partly a reaction to their early legislative agendas. Barack Obama was warned that pursuing the Affordable Care Act in a global recession was dangerous politically, and he didn’t care. We had waited a half century for the chance to make big strides toward universal coverage and he wasn’t going to lose the chance.

Democrats can be smarter about protecting their most vulnerable members, but it’s in the nature of winning landslide elections that a lot of people vote for you who aren’t really supportive of your agenda. You shouldn’t govern with them in mind, even if there’s no reason to needlessly antagonize them.

If Biden wins big, he might be able to go further on climate change than is politically wise, and he should just go ahead and do that anyway because he has the power to do it and it needs doing. Sometimes, the right policy eventually becomes popular. Oftentimes, it takes longer than two years to make that journey. Certainly, Obamacare is better-liked today than it was when voters went to the polls in 2010.

What I’m saying is that you don’t have to have a mandate, or even to believe you have a mandate. What you need is power.

I will say that one reason I am reluctant to jettison the legislative filibuster is that it will give the Republicans an easy way to undo every accomplishment if they ride back to power on backlash against policies that haven’t had time to ripen and gain widespread approval. Our problems may be urgent enough to justify it, put it isn’t a cure-all. Doing the right thing usually gets punished in the short-term, and that’s not a reason for inaction.