Ron Brownstein: “Since the 1970s, the share of voters who split their tickets—supporting one party for president and the other in Senate races—has steadily declined. If that pattern persists in November, Republicans will likely lose their slim upper-chamber majority because the most competitive Senate races are clustered in blue or purple states where Trump faces the greatest resistance.”
“To maintain control, Republicans will need either a dramatic Trump recovery in states such as Illinois and Wisconsin—or to convince more voters to split their ballots in Senate races than either side has typically persuaded lately. Neither will be easy.”