One thing we know is this: The universe of gettable Republicans is very small. The last national poll by The New York Times and Siena College found that 9 percent of Republicans planned to support Harris — a group that was slightly more likely to be female than male, and a bit more likely to be older than younger.

Three town halls in the Rust Belt on Monday underscored just how broad Harris’ push to win over GOP voters turned off by Donald Trump is.