Looking for His glorious appearing! Titus 2:13

Brushing aside warnings from Republicans, President Obama announced Thursday night that he is granting temporary legal status and work permits to nearly 5 million illegal immigrants, igniting a constitutional furor that amounted to a declaration of war against the incoming Republican majorities in Congress.

In a 15-minute prime-time address from the White House, Mr. Obama said his action is “lawful,” and said it offered a new deal for illegal immigrants who had been in the U.S. for at least five years: Come forward and register, pass a background check, and be granted a stay of deportation and a work permit good for at least three years.

“I know some of the critics of this action call it amnesty. Well, it’s not,” Mr. Obama said. “Amnesty is the immigration system we have today — millions of people who live here without paying their taxes or playing by the rules, while politicians use the issue to scare people and whip up votes at election time.”

The president also dared his Republican critics in Congress to counter him by passing a comprehensive immigration bill granting full citizenship rights to illegal immigrants, which Mr. Obama said he would sign, thereby wiping away his own executive action.

While the president portrayed his action as necessary to address long-standing immigration problems, gleeful Democrats, who held announcement parties across the nation, also believe Mr. Obama’s action will cement the party’s bond with the rapidly growing population of Hispanic voters and provide liberal candidates with a foundation for permanent success.

As Mr. Obama spoke, immigration activists outside the White House fence waved U.S. flags and held up signs proclaiming, “Gracias, Presidente Obama.”

GOP lawmakers have sought leverage to try to force the president to back down, or to find legislative ways to halt him in the coming weeks before his program has a chance to take full effect.

A number of House Republicans have said they should use the annual spending process to deny the president funding to carry out his plans.

But on Thursday the House Committee on Appropriations said that’s not a viable solution because the agency that would administer the program — U.S. Citizenship and Immigration Services — is fee-based and doesn’t need Congress’s money to operate.

Sen. Ted Cruz, Texas Republican, said that when his party takes control of the Senate next year, it should refuse to hold votes confirming all but the most critical of Mr. Obama’s executive nominations. He challenged Majority Leader-elect Mitch McConnell to commit to that plan.

In floor remarks Thursday, Mr. McConnell didn’t say what his party will do, but vowed it will do something.

“When the newly elected representatives of the people take their seats, they will act,” he said.

After Thursday’s speech House Speaker John A. Boehner said the president was abusing the democratic process and had shown he was “more interested in partisan politics than working with the people’s elected representatives.”

“By ignoring the will of the American people, President Obama has cemented his legacy of lawlessness and squandered what little credibility he had left,” the Ohio Republican said.

Mr. Obama will highlight the differences between Democrats and Republicans on immigration Friday at a campaign-style rally at a high school in Las Vegas, where Hispanics are an influential voting bloc.