New York Times: “Sitting vice presidents have a poor track record of succeeding their bosses. Over the last century, five have become their party’s presidential nominee. But only one — George H.W. Bush in 1988 — won the White House. Before Bush, the last sitting vice president to be elected to directly succeed the president he served was Martin Van Buren in 1836.”
“Incumbent vice presidents running for president face unique challenges. They must decide when to hug the president and when to hold him at arm’s length. They must claim credit for an administration’s successes even as their opponents blame them for its failures. Despite occupying a subordinate role, they must show they’re ready for the No. 1 job. And they must do it all while their boss, arguably the world’s most powerful person, watches.”