WASHINGTON (AFP) - A top Hillary Clinton staffer told CNN on Sunday that the former first lady's campaign team is unfazed by news that Vice-President Joe Biden is giving serious consideration to a White House bid.
"We'll let him make his decision," Jennifer Palmieri, Clinton's campaign spokeswoman, told CNN.
"However hard it is to secure the Democratic nomination is however hard it is. We have no illusions. We never thought that this was going to be easy," Palmieri said.
News late on Saturday that Biden is exploring a White House run had US pundits and politicos - including some already declared candidates - handicapping his odds of wresting the Democratic nomination from Clinton, widely viewed as the top contender.
A New York Times columnist reported on Sunday that his son Beau Biden, who died in May, at the end of his life encouraged his father to run for the US presidency.
Republican frontrunner Donald Trump was among those weighing in on Biden's odds.
"I think that Biden would have a good chance at beating her now," Donald Trump, the leading contender in the Republican race, told CBS television.
Controversy over Clinton's use of a private email server for State Department business may have tarnished her candidacy for some voters - at least temporarily.
"I think that the email scandal is going to be a devastating blow for Hillary," said Trump, who made the rounds of various political chat shows.
"I think she's got some very big problems," he said on Sunday.
"And you look at her poll numbers, they're coming down like a crashing rocket."
Biden, 72, has run unsuccessfully for the White House twice before, but news reports said he has said he feels more prepared than ever for the presidency.
Trump, 69, said however that he was less than convinced that Biden could prevail in a general election contest.
"I don't think that he's going to be that effective as a campaigner," the outspoken Republican business mogul said.
Democratic contender Bernie Sanders, 73, told ABC on Sunday he was unconvinced Biden offers Americans a substantially different option to Clinton.
"I think the American people who are seeing the middle class of this country disappearing, massive levels of income and wealth inequality, (and) a campaign finance system which is literally corrupt... want to go beyond conventional establishment politics," the socialist lawmaker told ABC News.
Dick Harpootlian, a former chairman of the South Carolina Democratic party and an outspoken booster for a Biden White House run, told ABC that the vice president's family seems generally supportive of his making another presidential bid.
"This isn't some snap decision. He really is weighing how this would impact his family, he said.
"My sense around the country is there's tremendous support there. He's got to gauge that. And then he's got to do a gut check," Harpootlian said.
In addition to apparent public unease over her emails, Clinton has been dogged by problems about her family foundation.
Republicans in Congress also have been holding her feet to the fire over her handling of the deadly 2012 attack on the US consulate in Benghazi, Libya which left three Americans dead.
She is scheduled to testify in Congress in October over the Benghazi affair.
Palmieri played down recent polls that have showed that voters find her boss, 67, less than trustworthy.
"She has the most money, and she's beating every Republican in most of the polls. So you can't really ask for much more than that," she said.