WASHINGTON — President Obama struck a defiant tone for his dealings with the new Republican-led Congress on Tuesday, calling on his opponents to raise taxes on the rich and threatening to veto legislation that would challenge his key decisions.

Dogged by an ailing economy since the start of his presidency six years ago, Obama appeared before a joint session of Congress for his State of the Union speech in a confident mood, buoyed by an economic revival that has trimmed the jobless rate to 5.6 percent and eager to use this as a mandate.

It is now time, he told lawmakers and millions watching on television, to “turn the page” from recession and war and work together to boost those middle-class Americans who have been left behind.

But by calling for higher taxes that Republicans are unlikely to approve and chiding those who suggest climate change is not real, Obama set a confrontational tone for his final two years in office.

He vowed to veto any Republican effort to roll back his signature healthcare law and his unilateral loosening of immigration policy. Any attempt to increase sanctions on Iran while negotiations with Tehran over its nuclear program are still under way would also be rejected, he said.

In sum, Obama appeared liberated: no longer having to face American voters again after his election victories in 2008 and 2012, a point that he reminded Republicans about.

“I have no more campaigns to run,” Obama said. When a smattering of applause rose from Republicans at that prospect, he added with a tight smile: “I know because I won both of them.”

Addressing Congress for the first time since Republicans seized the Senate in the November elections, the Democratic president made clear he will not back down from his political opponents, urging them to work with him to engage in a debate about the future “without demonizing each other.”

“Imagine if we broke out of these tired old patterns,” he said. “Imagine if we did something different.”

The core of Obama’s plan to boost the middle class is to raise taxes on the wealthiest Americans by $320 billion over the next 10 years to pay for expanded tax credits and educational benefits for the middle class, including two years of free community college.

Many of the proposals he outlined, while popular with many Americans, are unlikely to become reality, given Republican opposition and the fact Obama will soon become a lame duck as the county turns its attention to the 2016 campaign to succeed him.

But even if Obama’s wealth redistribution proposals are anathema to Republicans, they could be forced to consider alternative ways to tackle income inequality and prove they can govern, which could be a factor for Americans as they consider whether to elect a Republican as president in 2016.

And his moves could give an assist to  former Secretary of State Hillary Clinton, the overwhelming favorite for the Democratic presidential nomination if she decides to run.

Potential Republican presidential candidates Mitt Romney, who Obama defeated in 2012, and Jeb Bush responded quickly to the speech in Facebook postings, saying Obama was trying to use the tax code to divide people.

“Rather than bridging the gap between the parties, he makes ‘bridge to nowhere’ proposals. Disappointing. A missed opportunity to lead,” said Romney.

Obama also called for tax reforms to help small businesses in his State of the Union address, saying simplifying their tax return filing process would help reduce their costs.

“Let’s simplify the system and let a small business owner file based on her actual bank statement, instead of the number of accountants she can afford,” Obama said.

“ISLAMIC STATE”

At a time of riveting global crises, Obama’s speech was mostly about domestic issues and was relatively light on foreign policy.

He defended his decision in December to seek to normalize relations with Communist-ruled Cuba and urged Congress to lift the more than 50-year-old U.S. economic embargo against Havana.

He called 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.

Republican Senators John McCain and Lindsey Graham, two sharp critics of Obama, accused the president of bungling the battle against “Islamic State”, also known by the acronym ISIS.

“Despite the President’s claims of progress in the campaign against ISIS, this terrorist army continues to gain thousands of recruits and now controls significantly more territory in Syria than when U.S. airstrikes began there six months ago,” they said in a statement.

Obama reprised a promise he made when he first took office and vowed an unrelenting effort to close the U.S. military prison at Guantanamo Bay, Cuba, where foreign terrorism suspects have been held since 2002.

He had a message for both Democrats and Republicans on trade, where he wants to complete trade deals with Asia and Europe to create more export-related jobs.

He urged Congress to give him trade promotion authority, the power to negotiate free trade deals. Democrats have opposed giving him the power, fearing the deals he makes will hurt American labor.

Warning that China wants to “write the rules for the world’s fastest growing region”, Obama said both parties should give him the trade authority as a way of protecting American workers, “with strong new trade deals from Asia to Europe that aren’t just free, but fair.”