Abstract Using the extensive battery of issue questions included in the 2020 ANES survey, I find that a single underlying liberal-conservative dimension largely explains the policy preferences of ordinary Americans across a wide range of issues including the size and scope of the welfare state, abortion, gay and transgender rights, race relations, immigration, gun control and climate change. I find that the distribution of preferences on this liberal-conservative issue scale is highly polarized with Democratic identifiers and leaners located overwhelmingly on the left, Republican identifiers and leaners located overwhelmingly on the right and little overlap between the two distributions. Finally, I show that ideological preferences strongly predict feelings toward the parties and presidential candidates. These findings indicate that polarization in the American public has a rational foundation. Hostility toward the opposing party reflects strong disagreement with the policies of the opposing party. As long as the parties remain on the opposite sides of almost all major issues, feelings of mistrust and animosity are unlikely to diminish regardless of Donald Trump’s future role in the Republican Party.