With the arrival of the last weekend before Election Day, it's crunchtime for President Obama and Mitt Romney.
Heading into the last 72 hours of their fight for the White House, it's the moment in the campaign when the president and his challenger make their closing arguments, fine tuned to excite their committed supporters but not so partisan as to drive off the diminishing sliver of wavering voters still left to be won over.
This is when the battleground states truly live up to their names as the campaigns and their outside-group supporters engage in the final carpet-bombing of voters with seemingly ceaseless TV ads. It's when the foot soldiers of the campaigns, the volunteers in their comfortable shoes, make their final, street-by-street and door-by-door effort.
And it's when the campaigns narrow their vision not just to battleground states like Ohio, Florida and Virginia — but to specific counties within those states, as they focus efforts on areas in the states likely to be the most productive for them.
The presidential candidates, their running mates and top surrogates, are now focusing on media markets where the campaigns think last-minute appearances can provide the needed push to get less-motivated voters who might be inclined to vote for them to cast ballots either early or on Election Day itself.
No state looms larger in all of this, of course, than Ohio. With the Buckeye State seen as critical to Romney's path to the 270 electoral votes, Obama and Romney were both in the state Friday and returning there over the weekend.
Obama, who holds a small lead in Ohio according to most polls, is scheduled to visit Ohio at least twice over the weekend, going to Mentor in Lake County on Saturday and Cincinnati in Hamilton County on Sunday.
Romney is scheduled to visit Cleveland in Cuyahoga County on Sunday.
Obama won all three of these counties in 2008 when he defeated Sen. John McCain — Cuyahoga with 69 percent of the vote, Hamilton with 54 percent and Lake with 50 percent. In Lake, he topped McCain there by just 1 percentage point.
Obama could have a tough time matching his best 2008 margins in Ohio and elsewhere, since Republican enthusiasm is notably higher this year, according to news reports and polls.
Both campaigns are going to each other's strongholds in these last days before the election. On Friday, for instance, Obama went to Lima, Ohio, a small city where McCain got 30 percent of the vote four years ago.
Meanwhile, Romney's planned visit to Cleveland on Sunday is a way to return the favor. The city is the state's largest media market, which will allow the Republican to reach his supporters in the eastern end of the state.
And in a move that may be seen in retrospect as bold or unwise depending on the election's outcome, Romney also is scheduled to visit another bastion of Obama support on Sunday, the Philadelphia suburb of Yardley in Bucks County, Pa., a jurisdiction Obama won by 9 percentage points in 2008.
In recent days, the Romney campaign has suggested that Pennsylvania is in play and winnable. The Keystone State has been viewed for much of the election season by political analysts as safely in Obama's column. Despite the polls having narrowed there in recent weeks, Obama campaign officials and political experts still give Obama the advantage there.
Both candidates also have scheduled trips to Iowa, New Hampshire and Colorado over the weekend, three other battleground states where polls generally give Obama a slight lead.
Obama also plans to go to Wisconsin on Saturday, a state Romney visited Friday. Wisconsin is another state where the president once held a comfortable polling lead. But the fact that he's going this weekend suggests that it's tighter there than the president's team would like it to be at this stage.