1964 United States presidential election in Idaho

The 1964 United States presidential election in Idaho took place on November 3, 1964, as part of the 1964 United States presidential election, which was held throughout all 50 states and Washington, D.C. Voters chose four representatives, or electors to the Electoral College, who voted for president and vice president.

Idaho was one of 44 states carried by incumbent President Lyndon B. Johnson amidst his national landslide. However, it was Johnson's narrowest victory in the election. He carried the state by a margin of 5,363 votes, or 1.83%, making Idaho about 20.75% more Republican than the nation. Johnson’s strongest performances were in Clearwater and Lewis Counties in the heavily unionized Idaho Panhandle logging country, where he took over 76% of the vote. Goldwater’s strongest performance was in ancestrally Republican Jerome County, with 63% of the vote. While Johnson carried slightly over half of the state’s 44 counties, Goldwater carried most of the more populous counties (such as Ada, Bonneville, Canyon and Twin Falls), thus keeping the vote close.

This is the last presidential election where Idaho voted Democrat, and although Goldwater lost, this election continued the solidification of Idaho as a Republican stronghold. The state trended 13.02% Republican relative to the national swing. Kennedy had lost the state by 7.5% in 1960, but that was in a nearly tied national environment, while Johnson only just managed to carry it amidst a 23-point Democratic landslide nationwide. In eight counties, Goldwater earned a higher share of the vote than Richard Nixon had – a result observed in only nine other counties outside antebellum slave states. Apart from heavily Catholic Emmons County, North Dakota, Camas and Custer in Idaho were the solitary counties outside antebellum slave states to vote for Kennedy in 1960 and Goldwater in 1964.

No Democrat since Johnson has been able to get forty percent of Idaho’s popular vote, while the only Republicans to fail to pass fifty-five percent have been George H. W. Bush in 1992 and Bob Dole in 1996, in which Ross Perot's third-party candidacies (and that of Bo Gritz in 1992) played a part.

Analysis
At a more local level, the only counties in Idaho to have ever given a Democrat a majority or plurality since 1968 have been the ski resort counties of Teton and Blaine; and Bonner, Shoshone, Clearwater, Lewis, Nez Perce, Latah, and Benewah Counties in the Panhandle logging region. Of these, Bonner County was carried only by a narrow Bill Clinton plurality in 1992. The Republicans would go on to sweep all forty-four of Idaho's counties in 1972, 1980, and 1984, and all but one, Blaine County, in 2000 and 2004. Since then, only Blaine, Latah, and Teton Counties have been carried by Democrats, although rapidly-urbanizing Ada County (not carried by Johnson) has become strongly contested for Democrats since the late 2010s. As a result, this remains the last election in which Kootenai County, Bannock County, Elmore County, Gem County, Idaho County, Fremont County, Boundary County, Washington County, Valley County, Power County, Boise County, Caribou County, Bear Lake County, Adams County, and Butte County voted for a Democratic presidential candidate.