The two parties’ strongest messengers — a fraternity of recent presidents — descended on the pivotal swing state of Pennsylvania on Saturday to open the last weekend of this year’s midterms, rallying their voters in a proxy battle that could define both parties well beyond the election.

The moment represented both a clash from the past and a fight over the future. While the issues are distinctly 2022 — crime, high inflation and the unraveling of federal abortion rights — voters are again being asked to choose between the establishment politics of President Joe Biden and former President Barack Obama, and the chaotic, disruptive force of former President Donald Trump.

To press their case, Biden and Obama reunited in a familiar city, sharing a stage in Philadelphia — an event that brought back echoes of the enormous 2016 rally at Independence Mall where the party’s top leaders joined Bruce Springsteen and Madonna to try to push Hillary Rodham Clinton over the finish line. The stage at a Temple University gymnasium Saturday evening was a lot smaller — and the rally was a lot less well-attended than the 2016 event.