A new political survey shows that a quarter of U.S. Democrats polled want an unannounced candidate, Vice President Joe Biden, to be the party's 2016 presidential nominee.
The Bloomberg poll released Wednesday showed former Secretary of State Hillary Clinton with the support of 33 percent of Democrats surveyed, with Biden at 25 percent and an independent socialist Democrat, Vermont Senator Bernie Sanders, at 24 percent.
Several U.S. political surveys have shown that support for Clinton has waned amid continuing questions about her handling of U.S. classified material on her private email server during the four years she served as the country's top diplomat. Some surveys have shown Sanders surpassing her in two states, Iowa and New Hampshire, four months ahead of the first voting there in the long, drawn-out presidential nominating contests.
Biden has made numerous appearances at campaign-like events. But he has said several times he is undecided whether to join the Democratic presidential contest as he and his family mourn the recent death of his son Beau from brain cancer.
The Bloomberg survey showed Clinton's favorability rating dropping 10 percentage points, to 38 percent, from another poll by the news agency in April, while Biden's rose three points to 49 percent.
But on another question, whether voters had a "realistic vision" that certain candidates could become the U.S. president, Clinton topped the list.
She polled well ahead of Sanders and five leading contenders for the Republican nomination, billionaire real estate mogul Donald Trump, former Florida Governor Jeb Bush, retired neurosurgeon Ben Carson, Florida Senator Marco Rubio and former technology executive Carly Fiorina. Biden was not among the choices offered on the question.