Joe Biden’s announcement that he is running for president on Friday came as no surprise to his Democratic rivals in Iowa.
“You can imagine this, Biden came here before, and we had all the math worked out that we could win this one,” said Sen. Cory Booker, who is campaigning this weekend in the state.
The top three Democrats in the state polls — Sen. Bernie Sanders, Mrs. Clinton and Sen. Elizabeth Warren — were essentially conceding that their fans would follow Mr. Biden into the race.
“His years in the Senate are behind him,” Sen. Kirsten Gillibrand said. “He has earned the trust of people. He’s strong, honest and he’s a smart, caring man.”
Mr. Biden, Mr. Sanders and Mrs. Clinton all raised money for Mr. Giffords, the Arizona Democratic congresswoman who was shot in the head and has since made gun control one of her signature issues.
For his part, Mr. Biden made little secret of his willingness to play a bigger role in Washington after he leaves the Senate. During his wife’s endorsement in March 2017, he held her hand as he told her it would be her husband’s job to keep them in touch.
In a February appearance in Iowa, Mrs. Clinton told reporters that she understood Mr. Biden’s delay before deciding. “I think he’s always wanted to serve in the Oval Office,” she said. “You can only be so long a senator, and he certainly has said that. He deserves to be able to, you know, take his time.”
But as the race became more crowded, many saw Mrs. Clinton as a potential liability.
In North Carolina, two early voting states, Mr. Sanders and Mrs. Clinton were effectively tied in a CNN/ORC poll released Friday. Mr. Biden had even larger margins.