General Discussion
In reply to the discussion: I have a crazy idea. Joe Biden in 2020. [View all]Jim Lane
(11,175 posts)Yes, Obama, Bill Clinton, and JFK were in their 40s when inaugurated, but Carter and LBJ were in their 50s, and Truman was 64 when elected in 1948. (Among recent Republicans, Shrub was 54; his father and Reagan were both in their 60s.)
Another issue is that the Democrats' current national leadership pool does happen to skew older than in past years. For example, Al Franken is considered a fresh face, but he'll turn 69 during the 2020 campaign. Kirsten Gillibrand has attracted a few mentions for 2020, but even she (born 1966) would be too old by your criterion.
There's some enthusiasm on the left for Tulsi Gabbard, who'll be 39 by next Inauguration Day. Other than her, I don't recall anyone else under 50 even getting much mention. Another JFK, Clinton, or Obama in his or her 40s may emerge as a serious contender, but I wouldn't count on it.