Former labor union leader and independent candidate Dan Osborn has announced his bid for a Nebraska U.S. Senate seat, challenging Republican Sen. Pete Ricketts.

Independent Dan Osborn announced another bid to represent Nebraska in the Senate on Tuesday, challenging GOP Sen. Pete Ricketts after his loss in an unexpectedly competitive race against a Republican incumbent last year.

Osborn said he would take on Sen. Pete Ricketts (R-Nebraska) as an independent in a race that has already gotten President Donald Trump’s attention.