Has an electoral college voter ever voted against the voters popular choice?

Yes, there have been instances where electoral college voters have voted against the popular choice in their state. This phenomenon, known as a "faithless elector," occurs when a voter does not cast their ballot in accordance with the state's popular vote. Although rare, it has happened in several elections, with the most notable cases occurring in the 1796, 1872, and 2016 elections. However, the impact of faithless electors on the overall outcome is typically minimal, as most electors adhere to their state's popular vote.