U.S. President Barack Obama has denounced economic inequality in the United States, pressuring Republican lawmakers during a time which he describes as a “make or break moment” for the middle class.

Mr. Obama's speech Tuesday in the Kansas town of Osawatomie was meant to echo a historic address given there by President Theodore Roosevelt some 100 years ago.

Mr. Obama called for middle class Americans to be given a “fair share” and a “fair shot,” saying the United States should be a country where working people can raise a family, own a home and secure their retirement.

He said economic inequality hurts everyone and distorts democracy by giving an “outsized voice” to those can make unlimited campaign contributions and can afford high-priced lobbyists.

The president called for extending the current payroll tax cut, and for wealthier Americans to pay higher taxes.

Many Republicans oppose raising taxes on the wealthy, saying this would hurt the economic recovery.

The sluggish economy is expected to dominate the 2012 presidential campaign, in which Mr. Obama, a Democrat, is seeking a second term. The contenders for the Republican presidential nomination have blamed Mr. Obama for the nation's economic problems.