And now to the straight-ahead specifics of this election, the at-stake numbers, the candidates, the issues, the polls, and the voters themselves. Judy Woodruff begins.
JUDY WOODRUFF, NewsHour Special Correspondent: Jim, we'll start with the numbers, because control of the Congress comes down to simple arithmetic. Currently, Republicans hold 230 seats in the House; Democrats 201, with one independent who caucuses with Democrats, and two of the three vacancies Republican seats. And so Democrats would need to win 15 of those Republican-held seats to become the majority party in the House.
Now, currently in the Senate, Republicans hold 55 seats; Democrats 44, again with one independent who caucuses with the Democrats. Democrats would need to win 6 Republican Senate seats to move back into the majority there.
And now to the candidates. Most of the ones we began talking with months ago still are in races that are too close to call.
As NewsHour producers and correspondents fanned out across the country in June to launch our series of midterm election reports, President Bush's job approval rating already had dropped below 40 percent. It was a sign of trouble for campaigning Republicans in the House, especially those representing moderate districts in traditionally Democratic blue states: Connecticut, New York and Pennsylvania.
We visited several key districts in suburban Philadelphia. Republican incumbents Jim Gerlach, Curt Weldon, and Michael Fitzpatrick all were trying to strike a balance between embracing the president and keeping their distance.
REP. JIM GERLACH (R), Pennsylvania: We're not running to the president; we're not running from the president; we're not running with the president. We're running for the 6th Congressional District here in southeastern Pennsylvania.
REP. MICHAEL FITZPATRICK (R), Pennsylvania: I'm with the party and the president when I think he's right. And when I think he's not right, then I'm voting against him.
REP. CURT WELDON (R), Pennsylvania: He is the president, and I'm going to disagree with him repeatedly, which I've done.
JUDY WOODRUFF: But the three Democratic challengers were doing their best to knock the Republicans off-balance.
JOE SESTAK (D), Pennsylvania House Candidate: Curt Weldon has voted over four out of five times with this president. He is super-glued to this president.
PATRICK MURPHY (D), Pennsylvania House Candidate: Mr. Fitzpatrick agrees basically with this president and this Republican administration.
LOIS MURPHY (D), Pennsylvania House Candidate: Jim Gerlach has been part of the problem in Washington, that he's been voting with the administration, voting with George Bush.
JUDY WOODRUFF: We heard a similar exchange in New York's traditionally Republican 29th District. There, first-term Congressman Randy Kuhl tried to distance himself, not so much from the president, but from his decision to go to war in Iraq.
REP. RANDY KUHL (R), New York: I wasn't there when the authorization was given to the president to move ahead with the war. My predecessor was. I don't know how -- quite frankly, I don't know how I would have voted.
JUDY WOODRUFF: The Democrat, 24-year Navy veteran Eric Massa, has kept the race tight by trying to keep Kuhl connected to the war issue.
ERIC MASSA (D), New York House Candidate: ... and standing up and saying, "Well, I didn't vote for that," is a fundamental running away of responsibility.
JUDY WOODRUFF: And the war was a drag on Republican incumbents in three Connecticut districts. Nine-term Congressman Christopher Shays knew he might be in trouble but wouldn't distance himself from his decision to support the war.
GWEN IFILL: Are you willing to lose your seat on this issue?
REP. CHRISTOPHER SHAYS (R), Connecticut: Well, absolutely. I mean, I don't want to. But if I'm put in the back bench or thrown out, I'll know that what I was doing was fighting for something I believe in.
JUDY WOODRUFF: But the situation in Iraq hasn't improved. And in the view of most Americans -- many of them Republicans -- it has gotten worse. Republican strategists began seeing evidence of that weeks ago.
District by district, surveys showed Republican seats in blue states -- Illinois, Minnesota and Washington -- were slipping into the danger zone, as were red state seats in New Mexico, North Carolina, Florida, Kentucky, Ohio, and Indiana.
Indiana's 9th District is one of three in the state Republicans are having trouble defending. Voters here sent Mike Sodrel to Congress two years ago but only by a razor-thin margin. And that's when Republican prospects nationwide were better.
REP. MIKE SODREL (R), Indiana: I trust the voters will make the right decision in November. I think they're just kind of starting this process right now of thinking about, "Well, is this the fault of this president or this Congress or, you know, what about my member? Is he part of the solution or part of the problem?"
JUDY WOODRUFF: Baron Hill was the incumbent Sodrel defeated two years ago and told us he believes 9th District voters are ready to make another change.
BARON HILL (D), Indiana House Candidate: I think, in the final analysis, they're going to say, "You know, I don't know if the Democrats can do it any better than the Republicans or not, but let's give them a chance."
JUDY WOODRUFF: Florida also has three House districts it could swing over to the Democrats. Clay Shaw has represented one of them for 26 years and has risen to a senior position on the Ways and Means Committee. But Shaw, too, is in a tight re-election race, which he blames in part on the Mark Foley page scandal.
REP. CLAY SHAW (R), Florida: The problem that the Foley matter has brought about is that it's taken the good work that we've done, the accomplishments that we've done, the good news in the economy, and a lot of the progress that we've made in Iraq, it takes that off the front page.
JUDY WOODRUFF: But State Senator Ron Klein, Shaw's Democratic opponent, said the congressman has to accept some of the blame for the Foley scandal.
RON KLEIN (D), Florida House Candidate: Mr. Shaw is part of the leadership. He likes to talk about that all the time. He has to bear responsibility for the fact that the Republican leadership has, in this case, may have been involved in a cover-up.
JUDY WOODRUFF: Meanwhile, polls showed Democrats are within reach of taking back the Senate, as well, with better than an even chance of defeating Lincoln Chafee in Rhode Island, Rick Santorum in Pennsylvania, and Conrad Burns in Montana. Arizona was also one of their early targets, where border security and what to do about the country's estimated 12 million undocumented workers has dominated the political debate.
SEN. JON KYL (R), Arizona: Immigration is the issue in Arizona. More than half of the illegal immigrants coming into the United States pass through Arizona. Some stay. And everyone here is aware of it.
JUDY WOODRUFF: Two-term Republican Senator Jon Kyl staked out an enforcement-first position on the issue and made it the center point of his re-election campaign.
SEN. JON KYL: First of all, make sure that you have in place all of the things you need to secure the border, which will take time, but commit the resources necessary to it, and we haven't done that yet.
JUDY WOODRUFF: The immigration issue appears to be working for Kyl. He has maintained a steady lead in the polls throughout his re-election campaign.
Democrats believe they have a better chance in Missouri, where polls show first-term Republican Jim Talent might be out of step with the majority of his constituents on one hot-button issue: stem cell research. Talent opposes a ballot initiative to protect federally approved research from state intervention.
SEN. JIM TALENT (R), Missouri: I decided that I was going to look at this thing and make the decision that I thought was right and let the politics and the chips fall where they may.
JUDY WOODRUFF: Talent's Democratic opponent, Claire McCaskill, believes she'll benefit from some of the Republican support the stem cell measure is attracting.
CLAIRE MCCASKILL (D), Missouri Senate Candidate: I've particularly seen a lot of suburban women who feel very strongly about the stem cell issue, and that's a really important place for us to do well.
JUDY WOODRUFF: Democrats also believe they can take back one of the two Senate seats they lost in Tennessee in 1994. Will voters here choose the Democrat, Memphis Congressman Harold Ford? He would be the first black senator from the South since reconstruction.
REP. HAROLD FORD (D), Candidate for U.S. Senate: The only history we will make on November 7th is that everybody in Tennessee will have them a United States senator who will look out for them, who will stand up for them, who will love them, and who will represent them. Thank you.
JUDY WOODRUFF: Or will voters choose the Republican, former Chattanooga mayor and successful businessman Bob Corker?
BOB CORKER (R), Candidate for U.S. Senate: Look, I know I'm not as good-looking as my opponent. But when it comes to solving problems, you guys know that you can count on me to do that every single day in the United States Senate.
JUDY WOODRUFF: And Democrats are feeling confident about Ohio, where two-term Senator Mike DeWine is being tarred with the same brush as other problem-plagued Republicans.
SEN. MIKE DEWINE (R), Ohio: You know, we've had scandals in the state house in Washington or in the state house in Columbus, and that's been a problem. The president's popularity is certainly not what it was. The Republican governor's popularity is not where it should be, so there are issues there.
JUDY WOODRUFF: The Democrat, northern Ohio Congressman Sherrod Brown, is using the scandals and the state's sagging economy against DeWine.
GWEN IFILL: So this is a "throw the bums out" kind of year?
SHERROD BROWN (D), Ohio Senate Candidate: I think it's a "throw the bums out" kind of year, because of the arrogance of power, because of one-party government, and because this crowd in Washington, Mike DeWine and others, and this crowd in Columbus have betrayed middle-class Ohioans.
JUDY WOODRUFF: National Republican Party officials recently denied a report that they had given up on DeWine's campaign and had shifted money away from it. However, Republicans have moved more resources into Virginia, in an attempt to protect incumbent George Allen from a surging challenge by Democrat and former Navy Secretary Jim Webb.
They also believe they could steal a seat in New Jersey. There, polls show Republican State Senator Tom Kean, Jr., the son of the former governor, in a close race with Democratic Senator Robert Menendez. For Democrats, the loss of even one seat could put majority control of the Senate out of reach.