WASHINGTON (AP) — Short on time and tempers, House and Senate candidates in tight races are turning snarky and personal in their attacks on their opponents.

The stakes, and the unpleasantness, are highest in the race for control of the Senate, where Republicans need to gain four seats to win the majority — only three if Republican Paul Ryan becomes vice president and, in his role as Senate president, breaks any tie votes.

In Massachusetts, GOP Sen. Scott Brown witheringly mocks Democrat Elizabeth Warren’s claims of Native American heritage. In Montana, Democratic Sen. Jon Tester pummels Rep. Denny Rehberg for suing a local fire department. Nevada’s Sen. Dean Heller calls his opponent, Democratic Rep. Shelly Berkley, “the most corrupt” person he’s ever met.