Two years after Trump surprised many of the pollsters and prognosticators, a handful of forecasting efforts are attempting to predict the battle this fall for control of the House of Representatives — and trying to prove that they’ve incorporated hard-earned lessons from the presidential election. The latest entrant is a partnership between Ipsos, the international polling firm, and the Sabato’s Crystal Ball, the election-analysis site led by Larry Sabato, director of the University of Virginia Center for Politics. Their website — which launched Tuesday — will combine the Crystal Ball’s existi...