NEW YORK • Mrs Hillary Clinton's campaign, increasingly worried about the threat of a challenge from Vice-President Joe Biden, is making a sudden and urgent effort to throw roadblocks into his path.
After months of voicing doubt about a challenge from Mr Biden, Mrs Clinton's campaign operatives are viewing Mr Biden's entry into the 2016 presidential race as a serious possibility and are trying to rally the party's apparatus and its donors to her side.
They have flooded uncommitted Democrats with e-mail messages, phone calls and a plea for them to sign a letter, a copy of which was obtained by the New York Times.
In the letter, Democrats are asked to "pledge to support Hillary Rodham Clinton at the 2016 Democratic National Convention with my unpledged delegate vote".
On Saturday, hours before Mr Biden is to appear as the keynote speaker at the annual gala of the Human Rights Campaign, the most influential gay and lesbian political group in the country, Mrs Clinton will have breakfast with the group.
Next Tuesday, former president Bill Clinton will appear on The Late Show with Stephen Colbert, after an emotionally powerful appearance by Mr Biden that became a viral video among some in the Democratic Party.
Mr Biden has kept even his loyal supporters guessing about whether he will ultimately become a candidate. But the Clinton campaign is not taking chances.
A subtle critique is emerging from the campaign's allies about the potential vulnerabilities that Mr Biden would bring to the race.
This week, Mr David Brock, who created the pro-Clinton group Correct the Record, which is coordinating with Mrs Clinton's campaign, told Chicago Magazine his "gut" told him Mr Biden would not run because "he'll realise that at this point in his career, he can go out with everyone's respect and esteem".
Mrs Clinton's aides, speaking on condition of anonymity because they did not want to discuss strategy in public, said that the effort to mobilise Democrats behind her is a natural progression of her candidacy, and unrelated to Mr Biden.
But several Democrats who have been in close contact with the campaign say they see a new sense of seriousness among her advisers about the prospect of a Biden candidacy. Her team has been adamant they are not behind efforts to draw negative attention to Mr Biden, or to do anything to pressure him.
Mr Biden's allies have made it clear they are watching Mrs Clinton's poll numbers and the fallout over her use of a private e-mail account at the State Department.
And it has become increasingly clear that the activity by Mr Biden's associates to prepare for a potential campaign and to assess the amount of money and staff available to him has gained the attention of Mrs Clinton's operation.
In addition to wooing gay and lesbian Democrats at the Human Rights Campaign's gala on Saturday, Mr Biden and Mrs Clinton are expected to compete aggressively for the backing of African-Americans, who have a hugely favourable opinion of Mrs Clinton but who remain fiercely loyal to President Barack Obama, and could see Mr Biden's candidacy as a continuation and affirmation of the first black president's legacy.
NEW YORK TIMES