Early in 2000, Osborne announced that he would run in Nebraska’s 3rd District as a Republican. He had grown up in Hastings, one of the larger cities in the sprawling district, and claimed a home in Lemoyne, near North Platte, as his district residence. However, he hadn’t lived regularly in what is now the 3rd since at least 1964; for most of that time he’d lived in Lincoln, the heart of the 1st District. Nonetheless, due to his wide popularity in the state, he easily won the Republican primary, which was tantamount to election in what has long been one of the most Republican districts in the nation. He breezed to victory in November with 83 percent of the vote. He was reelected with no major-party opposition in 2002 and against an underfunded Democrat in 2004.

In Congress, Osborne’s voting record was moderate to conservative. He garnered a lifetime rating of 83 from the American Conservative Union.