Donald Trump oversaw a horrific pandemic response which led to several hundred thousand deaths and a terrible economy. In an election year. And despite Biden winning by ~10 million votes nationally, only actually won the presidency by less than a quarter of a million votes where the EC was concerned.
Trump was historically bad. Like, he was almost Hoover in 1932 bad. And Biden barely won. I think most people knew it was kind of a fluke that couldn't be counted on moving forward, but here we are. Trump's still out there, but he's not actually in office, so the whole "I'm not Trump, and my opponent is like Trump" strategy is failing a year later. Democrats need to stop running on what they aren't and start running on what they are and will do.
But, and here's the kicker, they have to actually do ****. That means Sinema needs to be brought into line. That means Manchin needs somebody to tell him to knock it off and be a team player when it matters. Independents are fickle assholes, which is why they're independents. At least the true independents are, not the "I'm an independent but I vote a straight Republican ticket every time and refuse to admit to being or register as one because I'm twa" independents. They need to be won over constantly.