First, do not make this election solely about Donald Trump. The idea that the challenger wants a campaign to be a referendum on the incumbent rather than a choice between two candidates is a staple of political conventional wisdom. It is also a mistake.
Trump has dominated the national conversation for five years. His flaws are known by all. The Democrats should want this to be a choice between competing, starkly different visions for the country. If it's all about Trump, Democrats will lose.
Second, find ways to frame this economy on your own terms. As Obama showed in 2012, the candidate who succeeds in defining the terms of the economic debate will win the election. Romney's entire strategy was to lay the blame for the sluggish economy at Obama's feet while claiming that his business experience made him better suited to jump-start the recovery.
But Obama won handily because he reframed the economic question before voters. Instead of an up-or-down vote based on the unemployment rate or weak growth, the Obama campaign turned a question of economic performance into one of economic fairness by focusing on how Romney's policies favored the wealthy over the middle and working class.
Third, get out of the liberal Twitter bubble. Finally, one of Romney's biggest errors was being stuck in the conservative news bubble. The only people truly shocked by Obama's victory, which was predicted by the polls and the various data models, was the Romney campaign.
The Democratic nominee needs to recognize that a lot of the voters we need see Trump very differently than most of us that populate liberal Twitter, watch MSNBC and listen to Pod Save America. According to polling and focus groups, despite a Cheesecake Factory menu's worth of scandal, they still see Trump as someone who represents change.
Finally, voters are not naive. Outside of the MAGA base, most have a pretty nuanced view of Trump. These impressions can and must be changed"in some cases with only a modicum of new information. But only if Democrats run against the person these voters see, not the person they know Trump to be.