The Indiana Right to Life political action committee has endorsed Indiana state Treasurer Richard Mourdock (R) in his bid to unseat Sen. Dick Lugar (R-Ind.).

Lugar, on the other hand, got some unhelpful praise from former Sen. Arlen Specter (Pa.), a Republican-turned-Democrat loathed by most conservatives.

"We cannot afford to give Richard Lugar the opportunity to help place one more activist judge like Elena Kagan or Sonia Sotomayor onto the United States Supreme Court," Indiana Right to Life Chairman Mike Fichter said in a statement. "Richard Lugar will give the President his rubber stamp approval for any nominee put forward for the Supreme Court, just as he did when he voted to confirm Elena Kagan and Sonia Sotomayor. Richard Mourdock, on the other hand, understands the dangers of judicial activism and will firmly oppose any Supreme Court nominee who does not hold to a conservative judicial philosophy that is rooted in the United States Constitution."

The conservative anti-abortion-rights group is the latest to back Mourdock over Lugar: The National Rifle Association, FreedomWorks, The Club for Growth and other conservative groups are already in his corner. A recent Democratic poll showed Mourdock trailing Lugar by six points.

Specter, appearing on C-SPAN Monday morning, gave a shout-out to Lugar. When he took a call from an Indiana voter, he responded by saying "Vote for Dick Lugar." The caller then said he was likely planning to, leading to a smile from Specter.

The former Pennsylvania senator, an avowed centrist, has long been hated by conservatives: he barely warded off a GOP primary challenge from now-Sen. Pat Toomey (R-Pa.) in 2004, and when Toomey planned another run in 2010 Specter left the party, became a Democrat and voted for a number of Obama's key legislative achievements, including Democrats' health insurance overhaul.

His comment was not missed by the Club for Growth, which immediately took it and posted it on YouTube. The group was a major player in the 2004 race against Specter, and Toomey ran it until he announced his second Senate run.

"The Club for Growth might think this is cute to package Sen. Specter's off the cuff comment as an endorsement," Lugar spokesman Andy Fisher said when asked about the Specter remark. "Clearly Club for Growth is part of a negative campaign that is devaluing the vital leadership we need in these serious times that is being provided by Sen. Lugar."

Watch Specter on C-SPAN here:

This post was updated at 2:36 p.m.