The Hawaii Government Employees Association Wednesday endorsed state Sen. Kai Kahele in his bid for the U.S. House seat representing rural Oahu and the neighbor islands, giving a substantial boost to a campaign that already appeared to be quickly gaining momentum.

The HGEA is the largest of Hawaii’s public worker unions with nearly 41,000 members.

Kahele announced more than a year ago he planned to run for one of Hawaii’s two much-coveted U.S. House seats, and has raised hundreds of thousands of dollars to fuel his campaign.

U.S. Rep. Tulsi Gabbard, who represents that district, announced in last October she will not run for re-election, clearing the field for Kahele, (D-Hilo).

Surprisingly, none of the top-tier political figures in Hawaii have announced yet that they plan to challenge Kahele for that seat in the Congress, and Kahele is using his early entry into what is now a wide-open race to steadily build political support for his campaign.

Former Hawaii Democratic Governors Ben Cayetano, John Waihee and Neil Abercrombie have all endorsed Kahele, 45.

Randy Perreira, executive director of the HGEA, described Kahele as a fellow union member who “is certainly well-versed in making sure that the voices of average working Americans can and will be heard in the Congress.”

Kahele, who is a lieutenant colonel in the Hawaii Air National Guard and was deployed to Iraq and Afghanistan, is a pilot for Hawaiian Airlines and a member of the Air Line Pilots Association International union.