Indiana State Treasurer Richard Mourdock (R) met with former House Speaker Newt Gingrich during his recent trip to Washington, D.C., to talk about his looming primary challenge to Sen. Dick Lugar (R-Ind.).

According to a source with knowledge of the meeting, Mourdock sought the support of Gingrich and his advocacy group, American Solutions.

The meeting with American Solutions was part of an extensive schedule of sit-downs with conservative groups in D.C., including meetings with the National Rifle Association, Americans for Tax Reform, the National Republican Trust PAC, the Club for Growth and GOP Sen. Jim DeMint (S.C.).

As Mourdock prepares to announce his run against Lugar, he has already lined up the backing of a majority of GOP county chairmen in Indiana. He has also been circulating an internal polling memo that shows Lugar vulnerable, according to a source close to the Mourdock camp.

The poll, which was conducted last month by Wilson Research Strategies, shows just 31 percent of likely GOP primary voters said they would vote to reelect Lugar, regardless of his primary opponent.

Lugar is barely above 50 percent on the ballot, which isn't a good starting position, but the memo doesn't mention Mourdock's percentage.

The source wouldn't confirm that Mourdock met with Gingrich, but said he utilized the polling memo as a sign of Lugar's vulnerability during his recent trip to Washington.

Mourdock will officially jump into the race on Feb. 22.