Hillary Clinton likes to tell voters what she’s not doing: running for President Obama’s third term.

That’s to downplay what she is doing: asking voters to pick a Democrat to occupy the Oval Office for 12 consecutive years.

Americans have agreed to do that just once in the past 179 years, and those unprecedented reelections of Franklin D. Roosevelt, the last as World War II neared its end, helped spark a constitutional amendment on term limits. The last nominee to win a third consecutive term for their party was Republican George H.W. Bush in 1988.