WASHINGTON — Republicans intensified their confrontation with the White House on Thursday as the party’s Senate leader defended his controversial assertion that a top GOP priority is to make Barack Obama a one-term president.

Sen. Mitch McConnell of Kentucky said the Republicans’ steadfast resistance to Obama contributed to Tuesday’s electoral romp and that defeating the president in 2012 remains a leading priority. McConnell’s comments, before a conservative Washington think tank, came as congressional leaders and the White House continued adjusting to historic shifts in political power in Washington. McConnell vowed to attack the administration’s health care overhaul in coming months and to pursue other top GOP goals.

Obama invited congressional leaders to dinner Nov. 18 at the White House in one sign of post-election bipartisanship. The president faces a Republican-controlled House and a narrowed Democratic majority in the Senate when the lawmakers come to work in January, an unusual split. McConnell previewed the tensions likely to develop between the strengthened Republican Party and its rivals.

“”Some have said it was indelicate of me to suggest that our top political priority over the next two years should be to deny President Obama a second term in office,”” McConnell said during a speech at the conservative Heritage Foundation. “”But the fact is, if our primary legislative goals are to repeal and replace the health spending bill, to end the bailouts, cut spending and shrink the size and scope of government,”” he said, “”the only way to do all these things is to put someone in the White House who won’t veto any of these things.””

The confrontational talk comes as Congress is preparing to reconvene later this month for a potentially long and difficult lame-duck session.

At the top of the agenda for that session is the thorny debate over extending the Bush-era tax cuts, which affect every taxpayer. Obama on Wednesday signaled a willingness to negotiate on his position that the reduced rates be extended only to those families making less than $250,000 a year, or $200,000 for individuals.

Republicans want the tax cuts extended to all Americans _ even those making more than $250,000. Upper-earners account for less than 2 percent of all taxpayers.

White House press secretary Robert Gibbs reiterated the administration’s willingness to negotiate on the issue Thursday, saying the tax cuts, which expire at the end of the year, will be a major item of discussion when Obama dines with eight Democratic and Republican leaders of the House and Senate later this month.

“”He’s certainly willing to listen to both sides,”” Gibbs said.

But the extra $700 billion it would cost to extend the breaks to wealthier households remains a divisive issue.

“”Making those tax cuts for the upper end permanent is something the president does not believe is a good idea,”” Gibbs said.

The House is undergoing a major upheaval as power changes hands from Democratic to Republican control. But in the Senate, neither side has shown a willingness to meet the other part way.

Sen. Harry Reid, D-Nev., the majority leader, said Wednesday that Republicans must be willing to compromise.

“”The ball is in their court,”” Reid said, fresh off his own hard-fought victory. “”We’re willing to work with you. You should be willing to work with us. This is not a one-way street.””

McConnell countered: “”If the administration wants cooperation, it will have to begin to move in our direction.””

Many Republicans have avoided gloating after Tuesday’s landslide. Rep. John Boehner, R-Ohio, likely to become the House speaker, toned down his rhetoric, while still making clear his opposition to Obama’s priorities.

McConnell, though, despite his outward air of a Southern gentleman, has emerged as a GOP bulldog. “”The mandate for change is directed at the other guys,”” he said. In both the chambers, GOP leaders face new challenges as they absorb into their ranks tea party-backed candidates who bring a rightward emphasis.