A Republican congressional agenda that includes major revisions in Social Security, tax cuts, creation of a national energy policy and expansion of trade with Latin America must now contend for time and energy with the hottest topic on Capitol Hill – a battle for the Supreme Court.

With the president appearing to push back his decision on a nominee to succeed Justice Sandra Day O’Connor until late July, Congress might be hard-pressed to achieve all it wanted to do in this first year of Bush’s second term _ the best time, history shows, to get a lot done.

“The legislative agenda has to be one of the factors in the president’s decision-making,” said Norman Ornstein, a congressional analyst at the American Enterprise Institute.

“A contentious nomination could tie up Congress for months and worsen the relationship between the two parties. That would be a double blow to the substantive agenda,” Ornstein said.

The Supreme Court vacancy has injected a tone of urgency into congressional calendaring, House GOP aides said.

With the Supreme Court nomination, as Sen. Brownback, R-Kan., put it, “sucking up all the oxygen,” there’s a narrow window this month for Congress to rush through a thick file of legislation before it breaks for the summer recess at the end of the month. But that would require agreements on legislation that look elusive as Congress takes off this holiday week.

Some legislative aides said that negotiations between the Senate on national energy policy and a six-year surface transportation bill might get an impetus from the pressure to clear the decks for the Supreme Court fight.

Senate Majority Leader Bill Frist, R-Tenn., asserts that he can shape a schedule in September that includes a Supreme Court debate and the other priorities on the White House and GOP agenda. Frist said he anticipates that the Senate in September will pass a budget bill that would extend previous tax cuts and make additional cuts, totaling $70 billion, along with trimming spending on federal programs by $35 billion.

His goal, said Frist, is to complete the confirmation before the high court opens a new session the first Monday in October.

Senate Minority Leader Harry Reid, D-Nevada, said Frist’s goal is doable, much more so if the president nominates a consensus candidate.

But with interest groups raising tens of millions of dollars for a confirmation fight, there’s the real possibility that some of these issues, plus others, might languish. Republicans also hope to revise and renew the Patriot Act, enact asbestos legislation and take a run at Bush’s top domestic priority _ a Social Security overhaul.

David John, Social Security analyst for the conservative Heritage Foundation, said “it’s the question of the hour” if Congress can take up Social Security during this session. Chances would increase, he said, “if hypothetically, the president nominated someone wildly popular.”

Since the House is not involved in the confirmation of a Supreme Court justice, its agenda is not likely to face the same kind of pressure as the Senate’s. One key measure GOP leaders hope to pass this month in the House is the Central American Free Trade Agreement.

Congressional leaders also hope to complete work this month on energy and highway legislation, each of which has provisions that would provide federal money for many members’ home districts.

But on these and other issues, congressional leaders might be fighting the clock. The occasion of a spotlight hearing on a Supreme Court nominee and a full floor fight on that nomination is not exactly the set of conditions that customarily galvanizes the Senate into quick action on any other pending business.

“When this nomination gets to the Senate floor, it will be the effective adjournment date for this Congress,” said Bill Frenzel, former GOP House member from Minnesota and now a scholar at the Brookings Institution.