Idaho has since become a Republican stronghold; as of 2020, this election marks the last time that Ada County, Canyon County, Gooding County, Jerome County, Lincoln County, Payette County and Twin Falls County would vote for a Democratic presidential nominee,[5][6] the last time that a Democrat would carry the state by double digits, and the last time that the state would (by margin of victory) vote more Democratic than the nation as a whole.
Republican nomination
William Borah, the Republican Senator for Idaho ran for the Republican nomination for president in 1936, the first candidate from Idaho to do so.
His candidacy was opposed by the conservative Republican leadership. Borah praised Roosevelt for some of his policies, and deeply criticized the Republican Party. With only 25 Republicans left in the Senate, Borah saw an opportunity to recast the Republican Party along progressive lines, as he had long sought to do. He was opposed by the Republican organization, which sought to dilute his strength in the primaries by running state favorite son candidates in order to ensure a brokered convention. Despite being easily the leading primary vote-getter, Borah managed to win only a handful of delegates and took a majority of them in only one state, Wisconsin, where he had the endorsement of Senator Robert M. La Follette, Jr. Borah refused to endorse the eventual candidate, Kansas Governor Alf Landon (who was nominated at the 1936 Republican National Convention), leading some to believe Borah might cross party lines and support Roosevelt. Ultimately, as he had four years earlier, he chose to endorse neither candidate.[7] Borah was on the ballot that fall in Idaho, seeking a sixth term in the Senate. For the first time since the people had been given the right to elect senators, the Democrats ran a serious candidate against him, Governor C. Ben Ross. Although Idahoans overwhelmingly voted for Roosevelt, who won every state except Maine and Vermont, Borah still took over sixty percent of their votes in his re-election bid.[8]