The Supreme Court has held that state legislators are absolutely immune from suit under § 1983 for actions in the sphere of legitimate legislative activity.

—construing 1983 in light of the immunity doctrine, the Court could not accept "that Congress... would impinge on a tradition [of legislative immunity] so well grounded in history and reason by covert inclusion in the general language before us," and therefore would not address issues that would arise if Congress had undertaken to deprive state legislators of absolute …

Federal common law extends the absolute legislative immunity granted by the Federal Speech or Debate Clause to state legislators.

Absolute legislative immunity attaches to all actions taken "in the sphere of legitimate legislative activity."

—"held that § 1983 did not abrogate the long-established absolute immunity enjoyed by legislators for actions taken within the legitimate sphere of legislative authority."

—limited legislative immunity to officials who were "acting in a field where legislators traditionally have power to act."

It is well established that federal, state, and regional legislators are entitled to absolute immunity from civil liability for their legislative activities.

Legislative immunity allows legislators to be free "from deterrents to the uninhibited discharge of their legislative duty, not for their private indulgence but for the public good... The privilege would be of little value if they could be subjected to the cost and inconvenience and distractions of a trial... or to the hazard of a judgment... based upon a jury's speculation as to …

—and that "it is not consonant with our scheme of government for a court to inquire into the motives of legislators,"

"... In times of political passion, dishonest or vindictive motives are readily attributed to legislative conduct and as readily believed. Courts are not the place for such controversies. Self-discipline and the voters must be the ultimate reliance for discouraging or correcting such abuses."