President Barack Obama gestures as he speaks at the Paramount Theatre in Austin, Texas. Picture: Jacquelyn Martin

Austin -

US President Barack Obama on Thursday laughed off Republican calls for his impeachment over his flexing of executive power to thwart their blocking tactics in Congress.

“You hear some of them. 'All right. Sue him. Impeach him’,” Obama said with a giggle.

“Really? Really? For what? You're going to sue me for doing my job?” the president told a Democratic campaign event in Texas.

Obama, who is drumming up hundreds of thousands of dollars for Democratic candidates who face tough races in mid-term elections, said he felt liberated to be out of Washington after a two-night political swing.

“I can just, you know, let her rip,” Obama said, castigating Republicans for hindering his plans to grow the economy, ease the burden on America's middle class and to make college affordable.

“I've got a better idea,” Obama, now in full swing, said. “Do something! If you're mad at me for helping people on my own, let's team up.”

There has been some talk on the right of the Republican Party of building an impeachment case in the House of Representatives - but this appears more a bid to swell campaign cash and attention than a serious attempt to unseat the 44th US president.

House Speaker John Boehner has ruled out impeachment - but is vowing to sue Obama for abuse of power in court.

Boehner realises that further polarising politics before November's mid-term elections would be a gift for Democrats keen to change the subject from the unpopularity of some of Obama's programmes and to highlight Republican radicalism.

Former Republican vice-presidential candidate Sarah Palin has added her voice to an official impeachment campaign.

Palin has said a current crisis sparked by thousands of Central American children illegally crossing the US border was “the last straw”.

“The many impeachable offences of Barack Obama can no longer be ignored. If after all this he's not impeachable, then no one is,” Palin wrote on, a conservative website.

Though the idea of impeachment seems far-fetched, the editorial page of The Wall Street Journal saw fit to weigh in on Thursday to warn conservatives off.

“The Constitution says a president can be impeached for 'treason, bribery or other high crimes and misdemeanours’,” the paper said.

“While Mr Obama's abuses of power are serious, they don't rise to that level.”

White House officials say that none of the steps Obama has taken in recent months - from implementing his signature health-care law to changing immigration policy and introducing measures to combat climate change, infringe legal limits on his power.

Nevertheless, keen to show momentum in a second term that has all but ground to a halt, the White House on Thursday released a list of 40 actions the president has taken this year to build “real, lasting economic security for the middle class and expand opportunities in order for every hardworking American”.

The last US president to be impeached was Bill Clinton, for lying under oath about his private life. Clinton was acquitted by the US Senate and Republicans faced a political backlash for overreaching.

The only other US leader to be impeached was president Andrew Johnson in 1868.

Impeachment proceedings were drawn up against Richard Nixon, but he resigned in 1974, before they were put to a vote in the House. - Sapa-AFP