NEW YORK, Sept. 24 -- Three polling organizations published results within hours of each other on Tuesday showing the same thing: independent voters in the United States are breaking for Democrats at a level that has historically preceded wave elections, and a near-majority of registered voters say their vote in November is primarily an act of rejection toward Donald Trump.

The convergence is not coincidental. The NPR/PBS NewsHour/Marist poll, conducted September 14-15 among 1,280 registered voters, found Democrats leading the generic congressional ballot 53 to 41 percent. Among independent voters alone, the margin was 57 to 32, a 25-point gap that, if it holds through November, would represent one of the most severe independent defectio...