Lonegan is running in the Oct. 16 special election to fill the seat of the late Sen. Frank Lautenberg (D), who died in June. He faces a tough race against Cory Booker, the mayor of Newark and rising star in the Democratic Party, who is leading in polls.

New Jersey Gov. Chris Christie (R) endorsed Lonegan on Wednesday. 

Christie set the special Senate vote three weeks before the general election on Nov. 5, when he is up for reelection. The move attracted criticism from some who said he feared Booker’s star power would trump his own, bringing Democrats to the ballot box who otherwise wouldn’t vote.

Both Christie and Paul are also seen as potential 2016 GOP presidential contenders. The two have clashed publicly in recent months over a range of policy issues, from government spending to Paul’s opposition to the National Security Agency surveillance programs.