evidence: The Congressional Progressive Caucus agenda, first shared with NBC News, doubles as a blueprint of political advice for how it believes President Joe Biden can win over progressives and young voters who are uninspired by his re-election bid ahead of a rematch with former President Donald Trump. [...] Progressives have had a rough two years, having been marginalized after Republicans took control of the House and steered the agenda rightward. Biden has broken with the left on issues like tougher asylum laws and crime. Some prominent Democrats, like Sen. John Fetterman of Pennsylvania and Rep. Ruben Gallego of Arizona, have eschewed the "progressive" label as conservatives have found success in associating it with the left’s most divisive ideas. Gallego, who is running for the Senate in his purple state, quietly left the progressive caucus. The caucus recently missed an opportunity to elect one of its members to a rare open Senate seat in deep-blue California, with two of them running and losing. [...] Some of the provisions in the new agenda represent items in Biden’s "Build Back Better" agenda that were left on the cutting room floor because of the thin majorities. Others could spark intraparty disagreements, including a far-reaching liberalization of the immigration system with a path to citizenship for people in the U.S. illegally. Yet other pieces resemble popular causes that progressives want Biden to get behind, like expanding Social Security and legalizing marijuana.