WASHINGTON -- With the political conventions behind them and three debates ahead, Barack Obama and Mitt Romney now race against the calendar toward Nov. 6.
They have two months to deploy millions of dollars in ads, catch those voters who cast ballots weeks before Election Day, and log umpteen miles in a handful of crucial states -- all while worrying what surprising news or candidate slip-up might set the whole enterprise on its ear.
Obama and Romney have huge staffs to help keep it all straight, of course, but you don't. So here, for the rest of us, is a user's guide to the last leg of the 2012 presidential campaign:
So far, polls show a tight race, but forget everything you've heard so far. In polling, only the newest numbers count -- and the numbers capture a clearer picture beginning in September. It's time to pay attention.
One obvious reason: Summer fun is over, and voters are finally following the campaigns. Polling from the Pew Research Center in 2008 showed the share following the campaign "very closely" just about doubled from 28 percent in late August to 57 percent just before Election Day. With the public more attuned to day-to-day developments, the potential for big shifts in the polls is amplified.
Another reason is less apparent: Many polls get more accurate in the final two months, as pollsters make refinements in their hunt for likely voters, the elusive target for election surveys.
Trying to reach voters -- and no one else -- means trying to pin down a group that exists only for one day (or a few, in the case of early voters) and whose demographic and geographic makeup can't be known in advance. That's because more people tell pollsters they plan to vote than actually do. In the final Associated Press-GfK poll before the 2008 election, 77 percent of adults said they were "completely certain to vote" or had already cast a ballot through early or absentee voting. Actual turnout among those age 18 and over was about 20 percentage points lower.
So pollsters use a series of questions to try to identify voters who are most likely to show up and weed out the rest. Every pollster's definition of a likely voter is different; for some, they evolve over the course of the final two months.
FOLLOW THE MONEY
Money is a huge factor in this election, and one of the hardest to track.
The presidential race is expected to cost $2 billion or more, between official campaign expenses and super PAC ad spending. It's the first election since federal courts unraveled rules that had restricted how money could be spent in political races.
Outside groups can now raise and spend unlimited sums of cash with the help of millionaires and billionaires, who sometimes hide their identities as donors.
The result is a gusher of ads flowing through Monday Night Football and prime-time sitcoms until Election Day.
Something to watch for: In some states, the TV ads may suddenly vanish. That's a sign that one of the campaigns has given up hope there and moved resources to a state that's still in play.
And watch how this plays out: Romney's side is far outspending Obama's. Can the president narrow the gap?
Romney and his super PAC allies have spent more than $245 million on ads since the general election began in early April, according to advertising tracking data obtained by The Associated Press. That spending began outpacing the Democrats in mid-July, and the trend is expected to continue. By comparison, Obama and super PACs working in his favor have spent roughly $188 million since April.
No one will know the total spending until after the voting is over. That's because the last campaign money reports before Election Day cover only through mid-October.
Watch for updates on campaign spending over the next two months, in reports to the Federal Election Commission due later this month and in late October.
JOBS, MONEY AND NUMBERS
This race is all about jobs and the economy, so government reports and stock market swings take on outsized importance.
The Labor Department reported sluggish job growth Friday, as employers added 96,000 jobs in August. The unemployment rate fell to 8.1 percent from 8.3 percent in July but that was only because more people gave up looking for work.
Romney immediately seized on the latest numbers as further evidence that Obama's efforts to fix the economy have failed. The president said the numbers weren't good enough but sought more time for the recovery.
The Labor Department will release two more monthly jobless reports, including one just four days before Election Day.
Also watch the Federal Reserve's actions when it meets next week. It could dramatically boost the sluggish economy by announcing a third round of bond purchases designed to push long-term interest rates lower. Fed action would send the stock market soaring and boost many people's retirement accounts, at least in the short term.
Congress returns for two weeks on Monday but probably will steer clear of the big election issues: taxes, deficits, health care, the economy and jobs. Its biggest task is passing a $524 billion spending bill to keep federal agencies operating through next March and prevent any possibility of a politically explosive government shutdown before the election.