COLUMBUS, Ohio -- It's still all about Ohio.
After a strong debate performance, Republican challenger Mitt Romney is intensifying his efforts in the state that's critical to his White House hopes, while President Barack Obama works to hang on to the polling edge he's had here for weeks.
Both candidates campaigned hard in the state Tuesday, the last day of voter registration ahead of Election Day.
"Find at least one person who voted for Barack Obama last time and convince them to come join our team," Romney told voters in Van Meter, Iowa, before heading to make a similar pitch in Ohio, where he was campaigning with New Jersey Gov. Chris Christie.
Obama, in Columbus, called out, "All right, Buckeyes, we need you." His campaign had buses nearby, ready to ferry supporters to voter registration sites.
As Obama wooed Ohio State University students here, and Romney focused on the Democratic bastion of Cuyahoga County to the north, there were signs the president's Ohio advantage was narrowing.
A new CNN poll showed Obama leading Romney 51 percent to 47 percent among likely Ohio voters. GOP strategists familiar with Romney's internal polling said the race was even closer -- within a single percentage point -- as Romney enjoyed a post-debate surge of support.
"There isn't any question that he has breathed new life and new energy into the Republican Party," Ohio Gov. John Kasich said yesterday, referring to Romney. "We're seeing that there is greater intensity among Republicans and a great willingness to get out and vote and participate than we're seeing with Democrats."
With 18 electoral votes, Ohio is such a key state for Romney that one top adviser has dubbed it "the ball game" as the Republican looks to string together enough state victories to amass the 270 Electoral College votes needed to take the White House.
No Republican has won the presidency without Ohio, and if Romney were to lose here, he would have to carry every other battleground state except tiny New Hampshire. Obama still has several routes to victory should he lose here.
Romney's schedule highlights his increased focus on the state: He's spending four of the next five days in Ohio, ahead of the second presidential debate on Long Island next Tuesday. Running mate Paul Ryan squares off against Vice President Joe Biden Thursday in Kentucky.
In Columbus, Obama was greeted at a rally at Ohio State University by enormous letters that spelled out "vote early," a plea to the young voters who buoyed him in 2008. "We're implementing our own game plan," Obama campaign spokeswoman Jen Psaki said.
Both campaigns and outside groups had spent more than $141 million on TV ads in Ohio through the beginning of October, one of the highest per-person spending rates in the country. Only more-populous Florida, with $150 million in ad spending, has seen a higher total.