Sen. Dick Lugar (R-Ind.), might get another primary challenger: Wealthy auto dealer Bob Thomas is mulling a run and will make a decision by the end of the month, according to an Indiana political newsletter, Howey Politics Indiana.

A Thomas campaign could be good news for Lugar, as Thomas will have to compete for the anti-Lugar vote with Indiana state Treasurer Richard Mourdock, a Tea Party favorite who has long been in the race.

On the other hand, Mourdock has struggled so far in the race — he has less than $300,000 cash on hand, compared to Lugars $3.8 million. Thomas is a self-funder who dropped $600,000 into a congressional primary last year against then-Rep. Mark Souder (R-Ind.), coming in second in that race.

Lugar has been a top target of conservative outside groups including Freedomworks and the Club for Growth because of some centrist positions he has taken in the past. The six-term senator voted for both of President Obamas Supreme Court nominees and for the Troubled Asset Relief Program that bailed out Wall Street in hopes of averting a financial collapse.

Some of those groups have been hesitant about Mourdock, though. If Thomas jumps in and proves himself a strong campaigner, they might show a willingness to back him.