NPR talks to three political scientists and gets three different answers.
1936 — “The Republicans tried to attack FDR for his New Deal programs, saying they were too expensive and moved the country toward socialism — sound familiar?”
1980 — “Young, unknown president is elected after an unpopular administration… economy in the doldrums, problems with Iran, sense of malaise. Republicans nominate the person who finished second place in the previous nomination… after a divisive nomination struggle.”
2004 — “You have an incumbent president running for re-election in a polarized and closely divided electorate… And the result is again likely to be a close election in which the outcome will come down to a few swing states.”