For only the second time in 50 years, Republicans control the Presidency and both houses of Congress and this time with the expectation that it will last more than a few months.
The shift, while tempered by the possibility of Democratic filibusters in the Senate, puts George W. Bush and GOP lawmakers firmly in control of the agenda on everything from tax cuts and spending to healthcare and national defense.
In short, the gain of at least two seats in Tuesday's vote removes what has been the main bottleneck to President Bush's agenda in Congress.
It could also have an important and immediate impact on the nation's courts, as votes come on dozens of Bush judicial nominations that have been tied up in the Senate Judiciary Committee.
Moreover, Jim Talent, as the winner in a Missouri special election, will be seated this month, allowing the Senate's party switchover to occur as the lame-duck session beginning Nov. 12.
Understandably, Republicans on Capitol Hill admit to jubilation. But they aren't gloating, because memories are still raw of how swiftly control can vanish, as when the surprise defection of Sen. James Jeffords of Vermont in 2001 derailed the last GOP hopes for control of the presidency and both houses of Congress.
When Sen. Trent Lott of Mississippi who is already calling himself majority leader regains the right to speak first on the Senate floor, he also picks up power to set the agenda. It means swift consideration of more tax cuts to stimulate the economy, an energy bill that includes drilling in the Alaskan wilderness, and a scaled-down prescription drug plan for seniors.
"The American people have indicated that they want the president, the Senate and the House to get together and get results," said Senator Lott yesterday. "They are giving us an opportunity show that we can produce results for the American people."
Here are what are likely to be signature issues for the 108th Congress:
More tax cuts to stimulate the economy. In addition to making repeal of the so-called "marriage tax" and the estate tax permanent, Republicans are ramping up to pass a series of smaller, targeted tax cuts. These include cutting taxes on corporate dividends and the profits of overseas multinational corporations, as well as acceleration of increase in how much individuals can put into a 401(k) and other retirement programs.
"Republicans now have the opportunity to get the tax changes they have always wanted. The administration has already begun arguing that the deficits do not matter," says Peter Orszag, a senior fellow at the Brookings Institution.
Homeland security. Delay in passing homeland-security bill was a GOP rallying cry in the last election, and will be one of the first issues Republicans revisit, as early as next week's lame-duck session. Democrats have argued that the president's plan undermines union bargaining rights, but several who made that case may have lost elections over it.
Social Security reform. Once viewed as the deadly "third rail" of American politics, GOP candidates such as Elizabeth Dole in North Carolina proved that it was possible to run on this issue and win. Still, privatization of even part of Social Security is still a highly controversial issue, and may be sidelined by a fight over tax cuts.
Energy legislation. Republicans claim a compromise over energy legislation is now more likely, including drilling for oil in the Arctic National Wildlife Refuge.
Prescription-drug legislation. Last year's budget resolution set aside $300 billion for a prescription-drug benefit that targets government help to needy seniors, but relies on private companies to provide benefits. This is the version preferred by the pharmaceutical industry, one of the top contributors to GOP campaigns this year. Insiders say that support gives the bill a fast track in the new Senate.
Quick vote on presidential nominations. More than 80 presidential nominations held up in the Democratic Senate will see quick confirmation votes. One of the top priorities for Democrats has been to keep the White House from tilting the federal bench too far to the right. Sen. Orrin Hatch (R) of Utah, who will be the new chairman of the Senate Judiciary committee, promises swift floor votes on judicial nominations.
"Unless the Democrats can make a sufficient case to win over a handful of moderate Republicans in the Senate, now the only recourse they would have is to filibuster," says Sheldon Goldman, an expert on judicial nominations at the University of Massachusetts at Amherst. "They would certainly make a stand on a Supreme Court nominee seen as too extreme."
Still, despite their powers to control the agenda and head committees, Republicans face obstacles to passing major laws. Sixty votes is the threshold for most votes, and Republicans will need to hold their own ranks and win over Democrats to achieve it. "The question for us is whether we will be able to hold all Republicans," says a senior Republican adviser.
Meanwhile, Senate Democrats may be heading into a bruising leadership battle of their own, as they pick up the pieces from one of the most disappointing elections for them in this century.