It’s official: The Democrats have a Hispanic voter problem.Support for the party’s presidential ticket among the voting bloc that was supposed to be a linchpin of what John B. Judis and Ruy Teixeira memorably dubbed “the emerging Democratic majority” fell from 71% in 2016 to 63% last year even as Joe Biden won the White House, according to the Associated Press.The numbers cited by Democratic strategist Brad Bannon were similar, showing that Donald Trump's “share of the Hispanic vote increased slightly from 28% to 32%. The Democratic losses among Hispanics were offset by gains among white suburban voters. There probably has been slippage in Hispanic support for Biden since then, and Democrats should be concerned.”In some key areas, however, the Hispanic swing to the GOP was more dramatic. Both South Texas and South Florida, for instance, saw double-digit increases in Republican support, including as much as 20 points in parts of Miami-Dade County and over 10 in the Rio Grande Valley.“One important thing to know about the decline in Hispanic support for Democrats is that it was pretty broad,” top Democratic data-cruncher David Shor told New York magazine after the election. “This isn’t just about Cubans in South Florida. It happened in New York and California and Arizona and Texas.”The situation in the midterm elections could get much worse for Democrats. Both parties were tied in the generic congressional ballot, which asks voters whether they...