Former Massachusetts Sen. Scott P. Brown announced Wednesday that he is making another bid for the Senate from New Hampshire.

The partisan divide of the 50 states is not an immutable fact of nature, but here’s how things look for the foreseeable future: 24 states are solidly red; 17 are solidly blue.

Throw in New Hampshire, North Carolina, and Minnesota—where Trump or Kamala Harris won by about four points or less—and America has nine purple states in total, representing 18 Senate seats.