This is basically what Republicans did. McCain in 08, Romney in 12. The whole time conservative activists complained bitterly that they were losing elections because they were not nominating "true conservatives". The RNC was putting their thumb on the scale to nominate squishy moderates believed to be more acceptable to the general electorate. The conservative activists, meanwhile, yelled and screamed that these squishes didn't represent a clear vision of conservativism, they were just focused group tested sound bites in suits, trying to appeal to everyone and actually appealing to no one. Voters didn't have a real choice, it was the uniparty kind of thing.
Then came Trump, bold no compromise vision for what his party and the country could be. Voters were willing to give something new a try. It largely sucked, so Biden a centrist squish was elected by a close margin just to restore sanity to government. Biden did do some big things, but he didn't communicate them well over his term, voters didn't see benefit, just more centrist squish politician talk stuff. So here comes Trump again, with a bold vision and a promise to shale things up. Voters were willing to put up with all the shit again just to have a politician willing to do something to visibly change their lives. Harris meanwhile ran safely to the centered, studiously avoided differentiating herself from Biden or staking out anything resembling a bold vision. Squish. No change, more of the same.
Dems need to stand for something, we need a vision we can offer to voters.
Probably more than that, Dems need a backbone to actually fight, and fight hard and dirty when needed. Voters are tired of gridlock and nothing changing. They elected the strongman because they figure he won't get bogged down in political bullshit, he'll just get shit done, even if it means breaking rules. It's ok to break some rules if your doing it to help me, say the voters. Not to say that Dems should go all authoritarian, but they should be able to convey that they are going to do everything they can to help people, they'll throw a few elbows of necessary, they'll get bloodied and bruised and do what it takes to help people.
No more "but Republicans blocked us" excuses. The Dem president should personally go to the house chamber and occupy it until a vote is taken. Dems leaders should round up union memebers and storm the board rooms of corporations funding Republicans blocking economic policies. Dems should be visibly fighting for people. No more moderate squishes.