“Another warning light is blinking for Senate Republicans: underperforming gubernatorial nominees in three crucial Midwest states,” Axios reports.“Strong candidates for governor can act as sheepdogs in tight Senate races, keeping Republican voters — and GOP-curious independents — moving in the party’s direction.”“That’s adding to GOP anxiety in Michigan and Iowa, where the Democratic gubernatorial nominees have led for much of the summer. In Ohio — a state President Trump won by 11 points — the governor’s race is tied.”