More form Bill McInturff’s deep-dive review of polling data, starting with this interesting chart showing party divides over presidents going back to Truman. First takeaway: Barack Obama’s presidency represents a clear break, with a step-increase in party polarization over previous presidents, but Biden is a more polarizing president than Obama.

Additional observations. George H.W. Bush’s narrow spread is an artifact of the poll being taken in the months after the short action of Gulf War I, which gave him a huge boost that he soon squandered. Jimmy Carter’s year-before number is interesting, showing that it was his own party that lacked enthusiasm for him.

Equally significant is that the two parties have widened on what they think are the most important issues facing the country: