Liberal Jewish groups will face a much more hospitable political climate -- but activists expecting rapid, dramatic results are likely to be disappointed. Orthodox groups, which have sided with the Republicans on some key domestic issues, will face new challenges as some of their top allies move into the opposition and some of their top priorities get derailed.
For liberal Jewish groups, the biggest change will be that the House will no longer automatically showcase the legislative priorities of the Christian right, no matter how extreme.
Over and over again, the House has passed bills such as the Public Expressions of Religion Act (PERA), which would make it much more difficult to sue in church-state cases, knowing that the Senate, with its different rules and narrower margins, would not act.
But such House actions weren't meaningless; they provided undeserved legitimacy to ideas that in any earlier era would have been regarded as extreme.
With Rep. Nancy Pelosi (D-San Fransico) as House speaker, extremist proposals from the religious right will be dead on arrival. The Republicans can waste a lot of time introducing them, but key Democratic committee chairs are unlikely to let them see the light of day.
While it will be much easier to block legislation emanating from the far right, passing bills that liberal Jewish groups favor won't be a cakewalk. Once again, the Senate will be the big obstacle.
With a 51-49 majority, Senate Democrats will find it hard to get the 60 votes needed to end filibusters. That means the Republicans can do what the Democrats did so effectively in recent years: talk to death bills passed by the House.
With newcomers like Senators-elect Jim Webb (D-Va.) and Bob Casey and the new leverage wielded by Sen. Joe Lieberman (I-Conn.), the Senate Democratic caucus could be significantly more conservative than in the last Congress.
Getting legislation through Congress will take bipartisanship and willingness to compromise. In the 109th Congress, Republican leaders often played to the conservative grandstands, treating Democrats as legislative pariahs. If the Democrats follow suit, the results will be the same: gridlock and division.
In the House, the incoming Democratic leadership has signaled it wants to move cautiously, emphasizing at the start legislation with a real chance of passage, like increasing the federal minimum wage, cutting prescription drug costs and reducing the interest on college loans.
Liberal Jewish groups may be disappointed with a Congress that could be more pragmatic and more risk averse than many expect.
An early test for the Democrats will center on tax and budget issues. Pelosi has promised to restore fiscal integrity after six years of runaway deficits. But the Democrats will be reluctant to cut vital health and social service programs to tame the deficit, and wary of anything that can be portrayed by their opponents as a tax increase.
With Democrats now in control of the Senate, it will become significantly easier to block nominees to the federal bench who are seen as extreme by liberal Jewish groups.
That means if Bush wants to avoid bruising battles he can't win, the only answer is to consult with the Democrats and look for nominees who, while conservative, are not outside the judicial mainstream. The stakes in the judicial wars will take a quantum leap if President Bush gets a chance to nominate a third Supreme Court justice.
Jewish groups that take liberal positions on church-state matters, abortion rights and gay rights will find the political climate improved, but legislatively, change is likely to be incremental, not revolutionary as the Dems seek to solidify this year's electoral gains and create a positive legislative record to carry them into 2008.
Orthodox groups face different challenges.
Organizations such as the Orthodox Union and Agudath Israel of America have made the faith-based agenda, advocated by President Bush and the Christian right, a top priority.
With the Democrats at the helm, new proposals for providing government money for parochial schools and religious charities are unlikely; the big question is whether the new leadership will try to undo existing programs.
The Democratic leadership could also initiate investigations of existing faith-based programs -- which critics say were implemented without oversight and accountability. At the same time, Orthodox groups will find common ground with the new Democratic leadership on issues such as stem cell research, housing and health resources issues.
Many political experts say that if the incoming Democratic leaders want to avoid the fate of a Republican Congress repudiated by voters, they will have to move quickly to act on serious problems that affect the lives of countless Americans.
That will require compromise and bipartisanship. The same will be required of Jewish advocacy groups across the political spectrum if they want to genuinely serve a community whose interests have been hurt by the partisan gridlock gripping Capitol Hill.