The phrase "to buy an election" means using money or resources to manipulate and control the outcome of an election in one's favor, instead of relying on fair and democratic processes. Full definition
If there is one bright spot in the 2016 election, it was proof that the lobbyists and big corporations can't buy the election. (politics.stackexchange.com)
«If Eliot Spitzer cared about democracy, he would participate in the city's campaign - finance program and not use his personal fortune to try and buy this election wholesale.» (politico.com)
CNN: Billy Graham buys election ads after Romney meeting The most famous and revered pastor in America, Billy Graham, is calling on voters to cast a ballot for their faith in full - page ads in the Wall Street Journal, USA Today and other newspapers. (religion.blogs.cnn.com)