Trump’s 3 paths to victory:
Court cases overturn enough fraudulent votes to win.
Legislatures in enough key states (such as Pennsylvania, Wisconsin, Georgia, Nevada, Arizona, …) convinced both (a) real winner in their state was Trump, but for the fraud, and (b) because of this, their constituents will kick them out of office if they don’t send a Trump slate of electors
Congress (House controlled, in a state-by-state vote by Republicans) similarly convinced on key votes on accepting Elector slates.
So … Biden must sufficiently hold courts, key state legislatures, and the House of Representatives to win. (R) controls these key state legislatures and the House (for these 1-state, 1-vote matters).
Popular opinion will influence both state and federal legislators, if strong enough (and even influence judges, though they will not admit as much.)
Trump has a strong influence on popular opinion, though main stream news and social media are aggressively attacking that influence.