Republican president hopeful Newt Gingrich has stepped up his criticism of US judges and the Supreme Court as chief rival Mitt Romney defended his record against likely Democratic attacks.
With close to two weeks before Republican voters start choosing their nominee, Mr Gingrich is courting the conservative primary voters he will need to win in Iowa and sustain his campaign against Mr Romney.
Mr Romney, meanwhile, is relying on superior organisation and a pile of cash as he looks beyond the primary to the general election, though he continues to struggle in efforts to attract conservative Republicans.
Polls in Iowa and nationally show Mr Gingrich ahead of Mr Romney in the race for the Republican nomination to take on President Barack Obama in 2012.
Mr Gingrich is looking to stay at the top in the Iowa caucuses in early January.
The two candidates and other challengers then will square off in New Hampshire, which has the first primary balloting in the US on January 10.
Mr Gingrich, in remarks on CBS's Face the Nation, took up a familiar rant popular with conservatives against the nation's court system.
"There is steady encroachment of secularism through the courts to redefine America as a nonreligious country and the encroachment of the courts on the president's commander-in-chief powers, which is enormously dangerous," Mr Gingrich said.
Mr Gingrich has mounted a broad attack on federal judges and the Supreme Court, arguing that they are legislating from the bench and have more control over the country than they should.
It is an argument that drew sustained applause during a debate last week in Sioux City, Iowa - and one that could have particular resonance in a state where Republicans fought a protracted battle with state Supreme Court judges over gay marriage.