Even for a nation that is, by now, used to drinking in political news through a fire hose, election night on Tuesday could be a difficult one to absorb.
More than 500 House, Senate and governor’s races will be decided, if not by the end of the night, then over the course of the nail-biting days ahead as write-in ballots are counted and recounts are requested.
Beyond the individual results, the nation will be looking at the returns for answers to bigger questions: Was this election about President Obama? How powerful a phenomenon is the Tea Party movement? How will the new Congress address the still-weak economy? What will it mean for the crop of likely 2012 Republican presidential candidates? Did anonymous campaign money sway the outcome?
Democrats made their last-minute appeals Monday. Michelle Obama headed to Las Vegas and Philadelphia as Vice President Joseph R. Biden Jr. traveled to Vermont and former President Bill Clinton raced up and down the East Coast. Mr. Obama hunkered down in the White House, conducting a few radio interviews and bracing for a rebuke that most pundits predict could be historic in its breadth.
On the eve of an election that could make him speaker of the House, Representative John A. Boehner of Ohio, the minority leader, rallied Republicans in Cincinnati, praising as “patriots” the voters who have the “audacity to speak up in defense of freedom, the Constitution and the values of limited government,” according to excerpts released by his office.
Here is a guide to some of the trends to watch for as the results come in.
EARLY DECISIONS Polls close in Kentucky first, at 6 p.m. Eastern time, so look to the races there for an early clue to how the evening is going. In the state’s Senate race, Rand Paul, the Republican and a Tea Party favorite, has been pulling ahead of Jack Conway, the Democrat. Also watch Representative Ben Chandler, a Democrat who won re-election easily in 2006 and 2008, but is fighting to survive in Kentucky’s Sixth Congressional District.
In Virginia, Mr. Obama and his political team will be nervously watching the returns in the Fifth Congressional District, where Representative Tom Perriello, a freshman Democrat who voted for the health care bill and Mr. Obama’s other major initiatives, is seeking to hold on in a conservative part of the state.
In Ohio, five close races could help decide whether Republicans can quickly claim to have retaken the House from Speaker Nancy Pelosi and the Democrats. Keep an eye on seats held by Representatives Charlie Wilson, Zack Space and John Boccieri, each of whom is in a tough fight with his Republican challenger.
Gov. Edward G. Rendell of Pennsylvania, a Democrat, said he would be watching returns to see how Democratic turnout compared to 2008. “If there is a dramatic falloff, Democrats are cooked,” Mr. Rendell said.
THE TEA PARTY An analysis by The New York Times last month found that 138 candidates for the House and Senate claimed support from the Tea Party movement, and dozens of them could find themselves part of a Congressional Tea Party caucus on Wednesday and in a position to exert substantial influence on the Republican Party.
But assessing the movement’s success will not be a simple numbers game. If big-name Tea Party favorites lose to Democrats in places like Alaska, Colorado, Delaware or Nevada, the Republican Party could be left with a decidedly mixed impression of the movement and a renewed debate over whether Tea Party fervor made it harder — not easier — for Republicans to seize control of the Senate.
The outcome of those contests will also help determine the political strength of former Gov. Sarah Palin of Alaska, the self-described godmother of the Tea Party, who has actively backed many candidates. Ms. Palin has sought to rescue the faltering campaign of Joe Miller, who won an insurgent campaign for the Republican Senate nomination in Alaska but is in a close race with the write-in campaign of the woman he beat in the primary, Senator Lisa Murkowski. Democrats have some hope that they could snatch the seat if Republicans split their vote.
THE OBAMA MAP As the night wears on, one thing may become clearer: the extent to which Mr. Obama faces a new political reality as he begins to think about re-election in 2012.
Among the most telling indicators will be the outcomes of a handful of races for governor in important states Mr. Obama won in his 2008 campaign against Senator John McCain of Arizona. Those include Colorado, Florida, New Mexico and Ohio.
In Florida, the contest between Alex Sink, the Democrat, and Rick Scott, the Republican, drew to a tie in polling in the waning days before the election. A victory for Mr. Scott would put a crucial swing state under the control of Republicans.
The same can be said for Ohio, where Mr. Obama made a late visit on Sunday to bolster the chances of Gov. Ted Strickland. The Democratic Party is bracing for losses across the Midwest, so a victory by Mr. Strickland in Ohio would give the White House a bit of good news in that region heading into next year.
In the end, though, Mr. Obama’s future may be determined by his ability to once again win a handful of Western states. Two races to watch: campaigns for governor in Colorado, which appears likely to be a solid Democratic victory, and New Mexico, which is leaning Republican.
THE MONEY As the tide turned decidedly against the Democrats this fall, Mr. Obama and his allies took aim at a flood of money outside groups were spending on behalf of Congressional Republicans. They argued that the money would corrupt the process and provide an unfair advantage to their rivals.
That thesis will be tested Tuesday across the country in races like the one in Iowa’s First District, where outside conservative groups poured in close to $1 million to help defeat Representative Bruce Braley, a Democrat. In North Dakota’s at-large House seat, outside groups spent more than $2.4 million in a state where that much buys plenty of ads.
Outside groups, including American Crossroads, a group the Republican strategist Karl Rove helped start, put more money into Colorado’s Senate race than any other in the country — a total of $25 million. If Senator Michael Bennet, the Democrat, loses there, Mr. Obama and his allies will no doubt point to Colorado as the prime example of their frustration about special-interest money in politics.
THE BLUE DOGS Conservative Democrats in the South won big in 2006 and 2008, edging out their Republican rivals in House districts that could have easily tilted either way. If they lose this time around, Republicans could solidify their grasp on the region.
Look for the outcomes in races like Representative Heath Shuler’s re-election bid in North Carolina’s 11th District. A loss by Mr. Shuler would indicate that even the most conservative Democrats are having a hard time this time around.
In Georgia, Representative Jim Marshall, a Democrat, is seeking to remain in office in part by promising not to support Ms. Pelosi for speaker.