The driver, a twenty-five-year-old immigrant from Colombia named Joan Sebastián Durán Guerrero, had been shot and killed by an ICE agent. Now, as the prospective candidates in Maine rushed to express their outrage at Guerrero’s death, it was obvious that the retreat had been temporary. The fast-approaching 2026 midterm elections present the Democrats with both an opportunity and a crisis. Americans now tell pollsters that they are more likely to vote for Democrats than for Republicans this fall. One theory heard often in politics is that the Democrats are repeating, in ideological inverse, the experience of the Republicans in 2010, when the Tea Party overtook the G.O.P., eventually clearing the way for Trump.