If Democratic Party candidates win a majority in the Senate or House of Representatives in the November 7 congressional election, the party would gain control of key committees overseeing government operations.
A Democratic majority in one or both houses of Congress would mean Republicans would have to give up coveted chairmanships that allow the majority party to shape the congressional agenda.
With opinion polls indicating Democrats have a greater chance of winning control of the 435-member House of Representatives, more media attention, and Republican campaign rhetoric, has focused on who may control key committees there than in the 100-member Senate.
If Democrats won control of the House, they would select committee chairmen, and would also vote to make Nancy Pelosi the first woman ever to be Speaker of the House.
The House International Relations Committee would likely be headed by California Congressman Tom Lantos, known for his fiery speeches on behalf of human rights, tough rhetoric toward regimes in Iran and Syria, and his strong support of Israel.
"Israel is not facing just the terrorists Hamas and Hezbollah," said Mr. Lantos. "Those criminal groups are merely proxies for the real masters of terror, Syria and Iran."
In the House Armed Services Committee, Congressman Ike Skelton would likely use his chairmanship to focus greater scrutiny on Pentagon spending for U.S. troops and equipment, as well as spending in Iraq.
In Congress since 1976, Skelton has become one of the sharpest critics of the Bush administration's handling of Iraq.
"Continuing violence in Iraq underscores two facts - that the administration has failed not only to bring about stability for the Iraqi people, that American intervention in Iraq is inhibiting our counter-terrorism efforts in other parts of the world, and, thirdly, the military of the U.S. is less ready today than it was when we went into Iraq," he said.
Republicans are bracing for the possibility American voters will make them the minority in the House, and they are aiming their campaign criticism at two Democrats who would head two of the most powerful committees on Capitol Hill.
New York's Charles Rangel, the gravel-voiced critic of administration economic and foreign policy, and four-decade veteran John Conyers of Michigan, would head the Ways and Means, and Judiciary Committees respectively.
Both have been key targets of Republican campaign advertisements and speeches delivered by President Bush in support of his party's candidates.
"The person that wants to become head of the Ways and Means Committee for the Democrats said that he can't think of one tax cut that he would extend," said Mr. Bush. "That's code word for, get ready, if the Democrats take the House, your taxes are going up."
Congressman Conyers has been an irritant for President Bush on issues ranging from prewar intelligence on Iraq to the Patriot Act, legislation Congress approved giving the government new powers to fight terrorists.
In 2004, Conyers led Democratic calls for the resignation of Secretary of Defense Donald Rumsfeld over the Abu Ghraib prison scandal, involving mistreatment of Iraqi detainees by some U.S. troops.
"And, we definitely still demand the immediate resignation of Donald Rumsfeld," said Mr. Conyers. "There is no way that we can timidly rationalize what his responsibilities are as secretary of defense, an experienced secretary of defense, that had to have known what we were allowing to be done in these camps."
Bush political adviser Karl Rove has also used campaign appearances to criticize lawmakers like Conyers and others he asserts would weaken U.S. efforts to fight terrorists.
"The problem for these Democrats is that policies and votes have consequences, and their policies and their votes would make us more, not less vulnerable, and, in war, weakness invites and emboldens your enemies, and it is an invitation for disaster," said Mr. Rove.
A Democrat who may be in a position to subject government operations to the most scrutiny is Congressman Henry Waxman, who would head the House Government Reform Committee.
Frequently chiding Republicans for what he calls their failure to conduct proper oversight, Waxman would use committee subpoena powers to probe more deeply into reported waste and fraud by U.S. contractors in Iraq, and alleged connections between White House officials and convicted former lobbyist Jack Abramoff, who has tainted both Republican and Democratic lawmakers.
One choice facing the Democrats and potential Speaker Pelosi involves the House Intelligence Committee.
That panel saw often bitter feuding between its Republican chairman, Peter Hoekstra, and ranking Democrat Jane Harman, a potential choice to head the committee and a critic of Bush administration handling of military tribunals to try terrorist suspects.
"We do need tough aggressive policies, but they have to be consistent with our constitution and the moral authority of the United States," she said.
However, internal party politics could prevent Harman from getting the Intelligence Committee chair.
Besides Congressmen Rangel and Conyers, a Democratic majority in the House may bring additional African American lawmakers, and other women, into positions of power.
James Clyburn of South Carolina may compete for the post of Democratic Whip, the third ranking spot behind the Speaker and the Majority Leader. Mississippi Democrat Bennie Thompson would be in line to chair the Homeland Security Committee.
As the potential head of the House Rules Committee, New York Congresswoman Louise Slaughter would exert control over how legislation is amended before consideration by the House, a process Democrats have accused Republicans of manipulating to ram through President Bush's priorities with minimal debate.