“Senate Republicans are feeling increasingly bullish about expanding their majority next month,” Politico reports.

“Sen. Cory Gardner of Colorado, who chairs the GOP’s campaign arm, told national donors on a conference call this week that believes his party will win the vast majority of competitive Senate races according to a person who was on the call. Gardner’s sunny outlook envisions a Republican majority as brawny as 55 seats, a number that could put the GOP in the majority for years to come. Republicans currently control 51 seats.”

The FiveThirtyEight Senate forecast suggests the most likely outcome is that Republicans keep their 51 to 49 majority.

James Hohmann: “The president has told party poohbahs that he believes the midterms will primarily be a base election. His adopted party is likely to hold the Senate because this year’s best pick-up opportunities are in states he carried by double digits that are overwhelmingly white and heavily rural, where his immigration positions most resonate. GOP candidates, especially in red states, have followed Trump’s lead and made immigration a major theme of their advertising in the home stretch. The strategy might work.”