"This is when the cards go on the table," said Democratic strategist Tad Devine, a top adviser to past Democratic nominees Al Gore and John Kerry.
In the final two months, small headaches can be amplified and more voters pay attention, especially those whose minds are not made up. Obama and Romney both want to drive up turnout among their core supporters without alienating independents, who decide close races.
Obama will deploy his two chief Romney critics, Vice President Joe Biden and former President Bill Clinton, to states where they can try to narrow Romney's advantage with white working-class voters, including Ohio and Pennsylvania. He will dispatch San Antonio Mayor Julian Castro, the convention keynoter, and Los Angeles Mayor Antonio Villaraigosa to states with many Hispanics, such as Colorado and Nevada.
Michelle Obama will step up her efforts to maintain or expand her husband's advantage with female voters. She and the president will get an assist from Georgetown University law school student Sandra Fluke, who emerged as a leader in the fight over access to contraception and addressed the convention.
Romney is counting on Ryan to validate him with working-class voters in the Midwest, and his wife, Ann, to help convince women that he's on their side.
Obama is imploring voters to give his policies more time to take hold and trying to capitalize on two advantages: Polls find he is well-liked and more apt than Romney to understand people's problems.
In speeches and in ads, Obama and his team will remind voters that the president was raised by a single mother and saddled with student loan debt. They'll argue that the president understands middle class economic struggles because he has lived them, implying that Romney, who grew up wealthy, does not. That was a strong theme of the party's convention.
But for the Romney team, says adviser Kevin Madden, "it's about performance, plain and simple," on the economy and jobs especially.
The Romney campaign came out with 15 ads Friday for eight battleground states.
In Colorado and Virginia, the ads stress defense cuts. In Iowa, where unemployment is relatively low, the message is about the national debt and business regulation.
Obama's team is increasingly confident in the president's prospects in Nevada and Colorado, largely because of his advantage among Hispanics and women, so they see the election probably coming down to Ohio, Florida and Virginia.
Party operatives say Obama appears strongest in Ohio, where the economy is improving and the auto bailout is popular. Virginia remains tight, but Democrats see a path to victory through increased minority registration and last week's state ruling that conservative former Rep. Virgil Goode would appear on Virginia's presidential ballot. The president's aides say Goode could take a percentage point or two of support away from Romney, which could tip the balance.
It's Florida that makes Democrats most nervous. Their troubles in the state, especially with its Jewish voters, only increased during the Democratic convention. The party scrambled to reinstate words in its platform recognizing Jerusalem as Israel's capital after the omission drew criticism from Republicans.
Romney, who is already issuing mail brochures in battleground states, is expected to sponsor mail or radio ads drawing attention to the issue in Broward County and West Palm Beach, heavily Jewish communities in south Florida.
The race also is tight in New Hampshire and Iowa, with both sides campaigning in those states in the last two days.
It seems of particular concern for Obama. He's been to Iowa 10 times this year. Democrats claim it's a sign that he sees Iowa as insurance in case he loses elsewhere.
Republican Iowa Gov. Terry Branstad sees it differently.
"Obama has been back here again and again and again," Branstad said Thursday. "He knows he's in trouble here."