( L - R ) Clinton, Obama

CINCINNATI (Reuters):

Every politician in the United States presidential race claimed to be fighting for the middle class, and it seemed a sound strategy -until the Democratic frontrunners tried to define who, exactly, was middle class.

While Senators Hillary Clinton and Barack Obama couldn't agree during a recent debate whether someone earning US$97,500 or more could be considered middle class, voters have little difficulty judging who is not - the presidential candidates themselves.

"None of them really represent the middle class," said Rick Fulmer, 52, who works at the YMCA as a fitness trainer. "Both parties are tied to big business. It takes millions to run for president."

While Republicans and Democrats alike have appealed to middle-class voters for support ahead of the November 2008 presidential election, the sudden attempt to define that category has hit a nerve.

Sparring over tax policy during a debate in Nevada, Obama said those earning US$97,500 or more are among the top six per cent of income earners, and thus upper class. Clinton disagreed, citing incomes of firefighters and school supervisors.

While her rivals can try to paint Clinton as out-of-touch with poorer Americans in early voting states like Iowa, class has always been an ill-defined concept in America, where all but the poorest and richest consider themselves part of an amorphous middle class aspiring for better.

Census data show about a third of American households earned between US$35,000 and US$75,000 a year in 2005.