LINCOLN, Neb. (AP) — A Nebraska law approved last year without debate has set the nation’s highest hurdle for independent candidates to qualify for races such as governor and U.S. Senate, contradicting the state’s history of downplaying partisan politics.

Republicans hold every statewide office and critics say the measure was quietly inserted to an omnibus elections law to maintain that stranglehold.

The law gained attention after Republican Sen. Bob Krist on Wednesday quit the party to launch an independent run against incumbent Republican Gov. Pete Ricketts in 2018. A lesser-known independent, Doug Whitmore, hopes to run against Republican U.S. Sen. Deb Fischer.

The law requires independents in partisan statewide elections to collect signatures from at least 10 percent of registered voters. That’s a tall order in a rural state with only two major cities.