How Trump, infighting and flawed candidates limited Republican gains

Florida Sen. Rick Scott made a plea to about 35 of his colleagues during lunch at the National Republican Senatorial Committee offices in early August: Send money to the NRSC from your personal campaign accounts. The candidates were in need.

The Republican outlook had gone from glossy to grim since the July campaign finance reports. Despite $5-a-gallon gasoline and a historically unpopular president, Democratic Senate candidates in pivotal states had big financial and polling leads. First-time Republican candidates propelled by former president Donald Trump, on the other hand, were viewed...