Republican White House hopeful Mitt Romney

AFP

Republican White House hopeful Mitt Romney said President Barack Obama's campaign was "taking on water" Tuesday, as the rivals barnstormed across toss-up states while seeking swing votes two weeks before election day.

With their debates behind them, the candidates raced out of the blocks and onto the campaign trail, hoping to corral the most ballots from the shrinking pool of Americans still undecided in a race heading for a photo finish.

At a rally in Henderson, Nevada, Romney claimed he had the momentum, saying the debates have "supercharged" his White House bid and brought him that much closer to victory in November 6, reports AFP.

"His campaign is taking on water and our campaign is full speed ahead," he said.

The line was a clear swipe at the president's condescending comment during Monday night's debate when, reacting to Romney's repeated charge that the US Navy was undersized, Obama mocked his challenger by saying that working with the military was not like playing a game of "Battleship."

It was a fitting jibe that marked the venomous tone Tuesday, when Obama warned a rowdy Florida crowd that they cannot rely on his "reckless" and elusive Republican foe.

Romney was riding a tide of campaign optimism, however, and presenting himself as a voice of change, as he sought to peel away the states of Nevada and Colorado from Obama's column.

"His is a status quo candidacy. His is a message of going forward with the same policies of the last four years. And that's why his campaign is slipping. And that's why ours is gaining so much steam," Romney said.

He repeated his argument later Tuesday in Colorado, where running mate Paul Ryan and 12,000 other people joined him at one of the more spectacular venues of the entire campaign: Red Rocks, the natural amphitheatre above Denver which has hosted the likes of rock acts U2 and Coldplay.

"We're in the home stretch now, and I think the people of Colorado are going to get us all the way there."

At Obama's rallies, the president's beseeching tone and the new urgency in his appeals reflect his failure to sink Romney in the debates, as well as signs that it is the Republican, not Obama, who has momentum in the tight race.

Romney has consistently attacked Obama for failing to lay out a roadmap for the next four years.

To counter such claims, the president finally rolled out a book detailing his second term agenda and unveiled a new ad laying out his closing argument.

But Romney's senior adviser Kevin Madden mocked the publication as a "glossy panic button," saying the debates had reshaped the race in the Republican's favor and that Obama was running out of time.

Obama sought to nail Romney as a political shape shifter after his opponent presented himself as a sober man of peace in Monday's debate, toning down previously hawkish foreign policy positions.

He diagnosed the Republican as suffering from "stage three Romnesia," accusing him of misrepresenting and simply forgetting a litany of past positions in a win-at-all costs effort.

"We are accustomed to seeing politicians change their positions from four years ago, we are not accustomed to seeing politicians change their positions from four days ago," Obama said.

"You can choose the foreign policy that's reckless and wrong, or you can choose one that is steady and strong," the president said before heading to Ohio, the perennial swing state that may decide the election.

Later, in Dayton, Ohio, where one-in-eight jobs relies on the auto industry, he lacerated Romney over his opposition to an industry bailout he authorized in 2009.