In 1980, he sought a second term. In something of a surprise, his Republican opponent was Colorado Secretary of State Mary Estill Buchanan, a moderate candidate who narrowly defeated the more conservative choice, Howard "Bo" Callaway, in the party primary, by fewer than 2,000 primary votes. Fourteen years earlier, Callaway had been the Republican gubernatorial nominee in his native Georgia. Callaway in the early 1970s had bought and run an elegant resort in Crested Butte. Buchanan had hit Hart hard for supporting the Panama Canal Treaties and for backing then-President Jimmy Carter in 80% of his Senate votes. Buchanan charged in a campaign ad about Hart: "He votes one way and talks another when he is back here. He is a liberal, McGovernite carpetbagger." Hart responded that Buchanan's charges reflected her narrow viewpoint and insisted that his campaign would rise above partisanship. Said Hart in a campaign ad: "I will not ignore her. We will interact and debate, but I am going to run a campaign for the 1980s. What is her plan for the environment? For national defense? For the economy? It took me a year or so to formulate my ideas." In the end, Hart won narrowly, with 50.2% of the vote to his opponent's 48.7%.