COLUMBUS, Ohio (AP) — Republican presidential candidate Mitt Romney is promoting newfound enthusiasm for his candidacy as President Barack Obama highlights the success of American automakers in the wake of a government bailout. Both men are preparing for their second debate, set for Tuesday in New York.

Obama was hunkering down Saturday in Virginia to go over the game plan for the town-hall style debate with Romney. But his weekly official radio address spoke of an industry that’s critical to Ohio, another battleground state and perhaps the most important to his Republican opponent’s White House hopes.

The US president is not chosen by a nationwide popular vote but in state-by-state contests, making battleground states like Ohio — which are neither reliably Republican nor Democratic — important in such a tight election. Ohio is perhaps the most important of these states because no Republican has lost the state and gone on to win the White House.

“We refused to throw in the towel and do nothing. We refused to let Detroit go bankrupt,” Obama said in the address, a transcript of which was released early Saturday morning.

Romney opposed using government funds to help the auto industry go through bankruptcy. Many analysts believe the industry would not have survived if it had relied on private investment for rescue. It’s an issue that has dogged Romney in Ohio, where numerous auto parts suppliers also benefited from the survival of the big three automakers.

Romney is concluding a week of campaign rallies that saw him drawing larger, more excited crowds than he has through the fall campaign. More than 10,000 people turned out to several rallies, with the campaign saying that more people were signing up to attend events in the wake of Romney’s strong debate performance last week in Nevada.

“I’ve had the fun of going back and forth across Ohio, and this week I was also in Florida and Iowa, I was in North Carolina and Virginia. And you know what? There is a growing crescendo of enthusiasm,” Romney told a crowd of thousands at a sunset rally Friday in Lancaster, south of Columbus, where he and running mate Paul Ryan appeared together.

Saturday will be the fourth of the last five days Romney will spend campaigning in this industrial, Midwestern state critical to his hopes of winning the White House. His campaign swing comes as he and Republicans criticize Obama for the handling of the terrorist attack on the US Consulate in Benghazi, Libya.

Romney accused Vice President Joe Biden of “doubling down on denial” concerning security at the diplomatic post where the US ambassador and three other Americans were killed. During the vice presidential debate Thursday, Biden said “we weren’t told” about the Benghazi consulate’s requests for additional security. Although a State Department official told Congress on Wednesday about the requests, the White House said Friday that Biden was speaking just for himself and for the president.

“The vice president directly contradicted the sworn testimony of State Department officials,” said Romney, who was eager to stoke a controversy that has flared periodically since the attack. “American citizens have a right to know just what’s going on. And we’re going to find out.”

Romney plans to spend Saturday morning at a hotel outside Columbus, where he’ll meet with top advisers and get ready for his showdown with Obama in Hempstead, New York, on Tuesday. He returns to Massachusetts in the evening but first makes two campaign stops in Ohio.

After his widely panned performance in the first presidential debate, polls show Obama still holds a slim edge in Ohio. The state is crucial for Romney because his path to winning the 270 electoral college votes he needs to win the election is far narrower if he can’t win Ohio. Losing here would mean he’d have to win almost all of the other up-for-grabs battleground states.

Obama was in Ohio this week, too, but he was spending the weekend in Williamsburg, Virginia, preparing for the debate. The president has acknowledged he needs to turn in a stronger performance when the two meet again.

Obama and top aides plan hours of practice sessions ahead of the town hall-style event, including some mock exchanges with Democratic Sen. John Kerry, who is playing the role of Romney.

Campaign officials sought to keep details of Obama’s preparations secret. But they said the president was working on being more aggressive in responding to Romney and calling the Republican out on issues as well as pointing out what they maintain are Romney’s true positions.

Copyright 2012 The Associated Press.