WASHINGTON — The White House is preparing for a Republican attempt to impeach President Barack Obama as he takes executive actions on immigration and health care policies stalled in Congress, senior adviser Dan Pfeiffer said Friday.

“I would not discount that possibility” of an impeachment attempt, Pfeiffer told reporters at a roundtable hosted by the Christian Science Monitor in Washington. “The president acting on immigration reform will certainly up the likelihood that they will contemplate impeachment at some point.”

House Republicans are moving to sue Obama over his use of executive authority with the Affordable Care Act, and Pfeiffer said the administration is considering action to bypass Congress in dealing with immigration.

Pfeiffer’s remarks amounted to a political dare to Republicans and may serve to energize the Democratic voter base before the November congressional elections. While some tea party members of the Republican caucus in the House have expressed support for impeachment proceedings, House Speaker John Boehner has said he disagrees.

Polling shows there’s little sentiment in favor of impeachment among members of the public.

A CNN/ORC International poll released Friday found two- thirds of Americans do not support impeaching Obama, with the results divided along partisan lines.

Fifty-seven percent of Republicans, 35 percent of independents and 13 percent of Democrats support impeaching Obama, according to the telephone survey of 1,012 American adults conducted July 18-20. The poll has a margin of error of plus or minus three percentage points.

As the White House looks for strategies to help Democrats hang on to control of the Senate in difficult midterm elections, Pfeiffer and other aides have sought to highlight what they see as instances of Republican congressional overreach.

Forty-five percent of poll respondents said Obama has done too much to expand his powers, while 57 percent said House Republicans should not file a lawsuit against Obama.

The House Rules Committee Thursday approved a resolution to let Boehner sue the U.S. president for his use of executive power, in particular to adjust implementation of the Affordable Care Act without Congress’ votes. The full House may vote as soon as next week.

“Speaker Boehner, by going down the path of this lawsuit, has opened the door to Republicans possibly considering impeachment at some point in the future,” Pfeiffer said.

The U.S. Constitution says a president may be impeached by the House and removed from office if convicted by the Senate for “treason, bribery, or other high crimes and misdemeanors.”

“Impeachment is a very serious thing that has been bandied about” and “no one has made any allegation of anything” that would be “in six universes” a true cause for impeachment,” Pfeiffer said. At the same time “it would be foolish to discount” the idea Republicans would try it.