A DEFIANT Donald Trump renewed his attacks on a former Miss Universe winner, showing no sign of making changes to his strategy before his second TV debate with Hillary Clinton.
The outspoken Republican nominee instead pressed ahead with an aggressive approach focused on speaking directly to his white, working-class loyalists across the Midwest.
Democrat Mrs Clinton, meanwhile, pushed to improve her standing among younger voters with the help of the president, Senator Bernie Sanders and other key allies, 48 hours after a debate performance that seemed to spark badly needed enthusiasm.
New York businessman Mr Trump was on the defensive throughout the debate, particularly when Mrs Clinton highlighted his description of a former Miss Universe winner as "Miss Piggy" because she had gained weight.
Mr Trump condemned former Miss Universe Alicia Machado again on Wednesday night in an interview on Fox News, suggesting he was trying to save her job by shaming her into losing weight in the late 1990s.
He also cited unsubstantiated reports that she threatened a Venezuelan judge more than a decade ago.
Ms Machado says Mr Trump humiliated her by inviting reporters to her gym sessions and calling her "Miss Piggy".
"I helped somebody and this is what you get for helping somebody," Mr Trump told Fox.
Those closest to him insisted the Republican presidential nominee was satisfied with Monday night's debate.
But prominent voices within his own party called for more serious preparation next time following an opening confrontation marked by missed opportunities and mistakes.
Former House Speaker Newt Gingrich said Mr Trump should have been better prepared and he recommended the candidate work harder with skilled coaches.
South Carolina Senator Lindsey Graham said: "The only advice I could give him, and take it for what it's worth - prepare better."
But former New York mayor Rudy Giuliani, a key Trump ally and travelling partner, asked: "Why would we change if we won the debate?"
The next debate is 11 days away and Mrs Clinton conceded during the first one that she had taken some time away from the campaign trail to prepare for it.
Mr Trump told supporters at a rally in Council Bluffs, Iowa: "You see all the days off that Hillary takes? Day off, day off, day off."
He added, in a reference to his opponent's recent bout with pneumonia, which nearly caused her to collapse: "All those days off and then she can't even make it to her car, isn't it tough?"
Throughout his outsider presidential bid, Mr Trump has refused to deviate from a strategy hinged on an ambitious travel schedule packed with massive rallies that draw overwhelmingly white crowds.
Mrs Clinton, meanwhile, sought to transfer her widely praised debate performance into stronger support from women, young Americans and other critical voter groups, helped by her party's biggest stars.
President Barack Obama hammered the billionaire over his business practices and treatment of women in an interview aired on Steve Harvey's radio show, which is particularly popular among black audiences.
The Democratic president said his own legacy was "on the ballot" in November and suggested Mr Clinton was not getting enough credit, possibly because she is a woman.
And his wife, first lady Michelle Obama, accused Mr Trump of trying to undermine her husband's presidency for years by questioning his birthplace.
Mr Trump publicly admitted the president was born in America for the first time earlier in the month after spending years raising questions about the authenticity of Mr Obama's birth certificate.
"Trust me, a candidate is not going to suddenly change" once in office, Mrs Obama said at a rally for Mrs Clinton in Pennsylvania.
Hoping to broaden her appeal among "millennials," Mrs Clinton joined her primary rival, Mr Sanders, on the trail for the first time since they held a "unity" rally in July in an attempt to heal divisions within the Democratic Party.
Mr Sanders and Mrs Clinton promoted a plan they developed to make college debt-free for millions of students from middle-class and low-income families.
"None of this will happen if you don't turn out and vote," Mrs Clinton said at the University of New Hampshire.
Mr Sanders said: "It is imperative that we elect Hillary Clinton as our next president."
