UPDATE: Specter loses in Pennsylvania, Paul wins in Ky.

WASHINGTON — Veteran Sen. Arlen Specter of Pennsylvania, who switched parties hoping to prolong his career, lost his bid for a sixth term Tuesday night at the hands of impatient Democratic primary voters rejecting his plea to reward experience. Political novice Rand Paul rode support from tea party activists to a rout in Kentucky’s Republican Senate primary.

In another race with national significance, Democrat Max Critz won a special House election to fill out the term of the late Democratic Rep. John Murtha in southwestern Pennsylvania. Both political parties spent roughly $1 million to sway the outcome, and highlighted the contest as a possible bellwether for the fall.

On the busiest night of the primary season to date, Arkansas Democratic Sen. Blanche Lincoln led in her bid for nomination to a third term, but she was forced into a potentially debilitating runoff on June 8 against Lt. Gov. Bill Halter.

Taken together, the results were indisputably unkind to the political establishments of both parties. But any attempt to read into the results a probable trend for the fall campaign was hazardous — particularly given Critz’s victory over Republican Tim Burns to succeed Murtha in Congress.

David Espo/The Associated Press