Matthew Continetti explains at National Review Online why U.S. Sen. Bernie Sanders’ latest presidential bid seems familiar.

Trump shook the Republican Party to its foundations. He forced it to recognize his power, drawn not from Beltway credentials but from the Republican voter base. It was not that Trump remained unchanged. Beginning in 2011, he adopted core Republican positions such as support for the right to life, for the Second Amendment, for supply-side tax cuts, and for constitutionalist judges on the bench. Once in power he listened and sometimes deferred to Paul Ryan and Mitch McConnell. But the GOP changed more. It is no longer the party it was before Donald Trump. Never will be.

It might now be the Democratic Party’s time in the barrel. Among the Democrats who are declared presidential candidates, Sanders is in the lead. And he’s not a Democrat. Sanders is second only to Biden, who hasn’t announced his intentions. In one poll, Sanders is ahead of the former vice president. He leads the money race. Like Trump, his support comes from donations under $200. That’s not only a sign of appeal outside the major cities. It means Sanders has room to grow because the overwhelming majority of his donors have not given the maximum contribution.

Just as Trump did beginning in 2015, Sanders has established the ground of intra-party debate. Trump turned the 2016 Republican primary into a referendum on immigration, trade, and foreign policy. He came out ahead. Sanders has defined the parameters of the 2020 Democratic primary through his advocacy of Medicare for All, the Green New Deal, and much higher taxes on upper incomes. The antithesis of Trump’s nationalism is Sanders’s socialism. And socialism is hot right now thanks to Millennials and to Sanders’s Mini-Mes: Alexandria Ocasio-Cortez, Ilhan Omar, and Rashida Tlaib.