It is almost unheard of for presidents to come directly from the Senate. Of the forty-three presidents of the United States, only two—Warren Harding in 1920 and John Kennedy in 1960—moved straight from the Senate to the White House. Of the fifty-four presidential elections held since 1789, only fifteen saw current or even former senators win. Limiting the time frame to contemporary elections, some of the worst defeats were suffered by senators who had earned their parties’ nominations. Among others, Senators Barry Goldwater (1964), George McGovern (1972), Walter Mondale (1984), and Bob Dole (1996) lost by embarrassing margins. Of the last seven presidents, only Nixon had senatorial experience, and he had but a partial term as senator.
In a paper published two years ago in Political Science Quarterly, Barry C. Burden, a professor at Harvard University, laid out the long odds: Of the 54 presidential elections since 1789, 15 saw current or former senators win; from 1868 to 1972, 16 percent of senators who sought their party's nomination got it, compared with 48 percent of governors; and from 1960 to 1996, while sitting senators made up more than a third of those running for president, just 11 percent won party nods and 2 percent the general election.
"Of the 54 presidential elections since 1789, 15 saw current or former senators win"
Okay so that proves my point. Senators can get elected President.
"16 percent of senators who sought their party's nomination got it, compared with 48 percent of governors"
And that would explain why less than half were senators. What's your point?