Hillary Clinton on Friday denied her White House campaign was in disarray, despite sliding poll ratings and an uproar sparked by an aide who questioned her rival Barack Obama's drug history.
"If I had listened to ... the Washington chattering class, I would not be standing here would I?" Clinton told reporters, as controversy and reports of campaign turmoil swirled around her 2008 president bid.
"I believe in trusting my own instincts. I feel very, very good about the case that I am making.
Signs of new fragility in Clinton's 2008 bid came just 20 days before the first nominating contest in the race, the Iowa caucuses, and amid signs Obama is surging in the polls.
Clinton held a press conference a day after key New Hampshire powerbroker Bill Shaheen quit her campaign after saying Republicans would use Obama's admitted dabbling in drugs as a campaign issue.
Shaheen had told the Washington Post that Republicans would attack Obama for his past drug use, which the Illinois senator acknowledged as a folly of his youth in a memoir.
"It'll be, 'When was the last time? Did you ever give drugs to anyone? Did you sell them to anyone?'" Shaheen said.
The former first lady personally apologized to her rival on Thursday, in an embarrassment for her campaign, after seeing her lead in key early voting states disappear over a rocky six weeks.
Asked about reports that former president Bill Clinton was growing increasingly anxious about her prospects, and was plotting a shake-up Clinton said: "I don't now what you are talking about with these concerns. I really don't."
"We are just going to go out every day and work hard. That is the only way I know how to run my campaign."
Clinton also launched a new implied attack on Obama, strongly suggesting that he was not ready to serve as president in an era of testing foreign policy crises.
"I believe I am ready on Day One to be president."
While Clinton said she had apologized to Obama over Shaheen's remarks, which overshadowed a crucial last debate before the Iowa caucuses on Thursday, she declined several opportunities to say his use of drugs as a teenager would not be a future issue in the campaign.