But it is his experience itself that makes him such a risky bet for Democrats. Biden’s pledge to return government to a more civil era comes at precisely the time when more Americans than ever before want Washington to change its stagnant and stale ways.

Modern presidential history shows voters almost always prefer an outsider candidate who pledges to shake up Washington.

In the post-war era, the fresh new candidate has almost always beaten the experienced insider: Dwight Eisenhower was an outsider within his own party.

The fresh-faced John Kennedy beat a Senate majority leader and the sitting vice president. Richard Nixon returned, tanned, rested and ready, to beat a sitting vice president. Govs. Jimmy Carter, Ronald Reagan and Bill Clinton all defeated sitting presidents, and Gov. George W. Bush beat Clinton’s vice president.