The pro-business group's endorsement could mean big money for Hasner. The Chamber has been spending heavily on ads boosting candidates it supports and attacking incumbent Democrats in congressional races across the country.

Hasner is running in a redrawn Florida district currently held by Rep. Allen West (R-Fla.), who is running for reelection in a different district. Hasner will face the winner of the Democratic primary, where Lois FrankelLois FrankelFormer CIA director: Don’t call Russian election hacking ‘act of war’ Palm Beach official proposes Mar-a-Lago tax to pay for Trump visits Members jam with Wynonna Judd, Keith Urban at Grammys on the Hill MORE has the early lead.