Lean R / Lean D

A Lean R or Lean D rating means one party is favored, but the favored party would not be safe assuming any large national shift. The race is contested in earnest — both sides are spending, both campaigns expect to be on the air through October, and an unusual event in either direction could flip the rating.

The Lean band sits between Toss-up (no measurable advantage) and Likely (clear advantage barring an upset). The boundary is fuzzy on purpose; a race that drifts from Toss-up to Lean has produced enough signal — polling, fundraising, recruitment, the national environment — that calling neither party favored would be intellectually dishonest.

Most races that flip control of a chamber spend time in the Lean band; safe seats stay in Likely or Solid. Watching what moves into the Lean band over a cycle is one of the cleanest ways to read where a chamber is headed.