Support for the vice president is building as speculation grows about his potential entry into the 2016 presidential race, with 22 percent saying they’d back him. That’s ahead of Senator Bernie Sanders of Vermont, who was picked by 20 percent. The difference is within the poll’s plus or minus 5.3 percentage point margin of error.

Clinton, who continues to confront questions about her use of a private e-mail server while secretary of state in the Obama administration, has the support of 42 percent, down from 52 percent a month ago. Biden’s number is 10 percentage points higher than a month ago, while Sanders has seen a 4-point increase during that time…

Slim majorities of Clinton and Sanders voters say they would be at least somewhat likely to consider switching their support to Biden if he jumps into the race. The vice president isn’t expected to make a decision until at least the end of September.