The Ross Spano congressional campaign is boasting a string of endorsements it says show support on both sides of the Hillsborough-Polk County line.

The endorsement list put out by Spano, a Republican state House member from east Hillsborough, includes two of the five Polk County commissioners, along with Rep. Sam Killebrew, R-Winter Haven.

Spano is one of half a dozen candidates in the Republican primary for the District 15 U.S. House seat, which U.S. Rep. Dennis Ross, R-Lakeland, has announced he'll vacate when his term ends in November.

The district has traditionally been Lakeland-centered and held by a Polk resident, but the 2016 redistricting made Hillsborough dominant. It has 50 percent of the district's total voters to 36 percent for Polk and 14 percent for Lake.

Hillsborough has 48 percent of the district's Republicans.

Several Polk political leaders have expressed hope that a Polk resident can win the seat. The county, divided among three congressional districts, has no other resident member of Congress.

Three Polk County Republicans have filed for the race – former state Rep. Neil Combee of Winter Haven, prominent homebuilder Sean Harper and adoption counselor and GOP activist Ed Shoemaker – along with Spano, Danny Kushmer of Brandon and Curt Rogers of Dover.

Polk commissioners John Hall and George Lindsey backed Spano, along with several Hillsborough Republicans: Tax Collector Doug Belden; county Commissioner Al Higginbotham; former State Attorney Mark Ober; state Rep. Jake Raburn of Lithia; former state Rep. Rich Glorioso; and Plant City Mayor Rick Lott, former Mayor Randy Larsen, Vice-Mayor Bill Dodson and former city Commissioner Billy Keel.

Combee has previously announced endorsements from state Reps. Ben Albritton of Wauchula, Mike LaRosa of St. Cloud and Josie Tomkow of Polk City; former state Rep. John Wood of Winter Haven; Auburndale Mayor Tim Pospichal and Polk City Mayor Joe LaCascia.