DENVER (WTVB) - President Obama and Republican challenger Mitt Romney went at each other on the economy, taxes, and healthcare during their first 90 minute debate, last night inDenver. An aggressive Romney vowed to repeal and replace the landmark 2010 healthcare reform law, saying it is hurting job creation. Obama noted that the law was based on healthcare legislation Romney signed when he was governor ofMassachusetts. Most Americans say Romney turned in a stronger debate performance than the President. A CNN poll of debate-watchers found Romney was the winner of the first presidential debate by 67-percent to 25-percent.  A CBS News poll of undecided voters found 46-percent leaning toward Romney, 22-percent for Obama and 32-percent saying it was a tie.