Obama set to challenge GOP on tax benefits for middle class during State of the Union
President Barack Obama speaks about the Affordable Care Act in the Rose Garden of the White House on Oct. 21, 2013. Photo via Agence France-Presse.

President Barack Obama will challenge a skeptical Republican-led Congress on Tuesday to back tax increases on the wealthy to help lift up middle-class Americans in a State of the Union speech that will outline his vision for his last two years in office.

According to excerpts released by the White House of his 9 p.m. EST televised speech, Obama will say it is time to convert a recent surge in the U.S. economy into improvements for the middle class, many of whom are still experiencing hard times.

"Will we accept an economy where only a few of us do spectacularly well? Or will we commit ourselves to an economy that generates rising incomes and chances for everyone who makes the effort?” Obama will say.

Obama is proposing tax increases of $320 billion over the next 10 years to pay for expanded tax credits and educational benefits for the middle class.

The idea of raising the top capital gains and dividends tax rate to 28 percent from 23.8 percent is popular with Democrats who are looking beyond Obama's tenure to the 2016 elections. But it seems dead on arrival with Republicans who control both houses of Congress since their big election wins in November.

For Obama, seeking to burnish his legacy with two years left in office, the speech will be his best opportunity of the year to talk to millions of Americans watching on television about the improved economy six years into his tenure, which began with the Democrat facing a crippling financial crisis.

"At this moment – with a growing economy, shrinking deficits, bustling industry, and booming energy production – we have risen from recession freer to write our own future than any other nation on Earth. It’s now up to us to choose who we want to be over the next 15 years, and for decades to come," Obama will say.

On foreign policy, Obama will call on lawmakers to pass a new authorization of military force against Islamic State militants to replace powers that were given to President George W. Bush to prosecute the Iraq war.

He will say the U.S.-led effort to stop Islamic State from advancing in Iraq and Syria is working without dragging the United States into another ground war in the Middle East.

"This effort will take time. It will require focus. But we will succeed," he will say.

Obama will also urge Congress to pass cybersecurity legislation following a hack of Sony Pictures that the FBI has blamed on North Korea. Pyongyang denies responsibility.

“No foreign nation, no hacker, should be able to shut down our networks, steal our trade secrets, or invade the privacy of American families, especially our kids," he will say.

(Reporting by Steve Holland and Jeff Mason; Additional reporting by Roberta Rampton, Susan Heavey and Susan Cornwell; Editing by Grant McCool and Frances Kerry)