Now would be the time for him to act, because it will probably never be easier to build and harness bipartisan American support and demand to get rid of the massive influence of money in politics.
Sanders has repeatedly demonstrated he has bi-partisan support from the people. I even met a number of 'bi-partisan' Sanders supporters the night they voted right alongside me in the 2016 Colorado Caucus. They told me they would vote for Trump in the General if Sanders was not running.
Sanders can get bi-partisan support from the people easy enough, but he cannot afford to give the Republicans in the Senate more than a single chance to cross the aisle. And he certainly cannot be as accommodating as Schumer is.
Schumer has been in the Senate for how many years now? He still thinks the best negotiating tactic is to surrender at once without even being asked in the hope that by doing so, he'll make himself so attractive to the Republicans they'll want to do something for him.
Notice how those $2000 stimulus checks folks have been calling for somehow never made it the table? They were reduced to $1400 by the time they reached the starting gate. What's your bet at what amount they'll end up as if and when they reach the finish line?
2022 mid-terms are going to be happy times all over again for the Republicans at this rate.
To be honest, Schumer knows his negotiating tactic is bound to fail. That's why he sticks with it. Check out who donates to his campaign.