WASHINGTON (AP) - It could be President Barack Obama's best chance to outline his vision for the next four years.

Tens of millions are expected to watch on television as Obama delivers a State of the Union speech in which he's expected to draw a defining battle line with Republicans over fairness and the free market in America.

He'll be calling for the rich to pay more taxes -- just hours after potential Republican rival Mitt Romney released tax returns showing that he earned nearly $22 million in 2010 and paid an effective tax rate of about 14 percent.

House Speaker John Boehner (BAY'-nur) is already calling the themes of the speech a "pathetic" rehash of unhelpful policies.

Republicans are saying his answers are more of the same: higher taxes, more spending and bigger government.

One of Obama's themes will be economic fairness, which will include protecting the middle class and making sure the wealthy pay a fair share of taxes.

The formal GOP response will be delivered by Mitch Daniels, the Indiana governor and former White House budget director under President George W. Bush.