As Jonathan Rauch wrote in The Atlantic: “No one gets elected president who needs longer than 14 years to get from his or her first gubernatorial or Senate victory to either the presidency or the vice presidency.” Zero political experience is just fine with Americans. But too much is not. In the past century, voters have subjected their candidates to a freshness test. And 14 years of political experience seems to be a kind of expiration date. Most impressive, the Rule of 14 predicted the narrow defeats of Al Gore and Hillary Clinton, both of whom lost elections 15 years and 10 months after their first days in the United States Senate.

Biden, who leads almost every national poll, served as the senator from Delaware for 36 years, from 1973 until 2009, when he left his seat for the vice presidency. His 44 years of consecutive public service in Washington constitute one of the longest national tenures of any politician in American history. If Biden defeats Trump, the Rule of 14 won’t just get an asterisk; it will get a sledgehammer.

Any of the other three top Democratic candidates would also represent historic firsts. If Trump loses, it is all but certain that we will elect either the oldest president ever or the youngest. Bernie Sanders (78), Biden (77), and Elizabeth Warren (70) would all be older on their first day in office than the current record-holder in the oldest-president-ever category, Donald Trump. At 70 years and 220 days old on his first inauguration day, Trump was the oldest president to be elected to a first term, although Reagan in his second term was the oldest sitting president. Pete Buttigieg, 37, would be younger on day one than either Teddy Roosevelt—who, at 42, became the youngest president, after William McKinley died—or John F. Kennedy, who, at 43, became our youngest president-elect.