| SAN ANTONIO, Texas
SAN ANTONIO, Texas After 11 straight wins in the race to become the Democratic White House nominee, Barack Obama has reason to feel good and it is showing in his demeanor on the campaign trail.
There is a subtle air of confidence about the Illinois senator, even as he is quick to remind voters that he is not yet his party's nominee and that he lost to rival Hillary Clinton in New Hampshire in January despite expectations of a sizable victory.
"It's a tight race," Obama told reporters on Friday when asked how he felt about this week's crucial primary elections. "The Clintons are formidable."
Clinton must score significant victories on Tuesday, when primaries are held in delegate-rich Texas and Ohio, as well as Vermont and Rhode Island, to keep her presidential hopes alive.
Obama's solid performance in last week's televised debate and his interaction with crowds at rallies in Texas and Ohio illustrate a growing conviction that he is on a winning path.
At a rally the day after the debate, Obama, who usually plows into his regular speech directly upon taking the podium, basked quietly in the crowd's cheers while "City of Blinding Lights," the U2 song that signals his entrance to the stage, played on.
During the debate last Tuesday, Obama deflected smoothly the attacks on his health-care plan and ties to Nation of Islam leader Louis Farrakhan. But his quick look at Clinton, a senator from New York and former first lady, when they were asked about Russia's new president indicated to some that he preferred she take that foreign policy question first.
At other events Obama seemed to ignore Clinton altogether, directing more criticism at Republican front-runner John McCain in a preview to what he clearly hopes will be a general election fight ahead of November's election.
CONFIDENT, NOT ARROGANT
"Senator Obama's confidence has grown as his political successes have grown," said Ed Dorn, a professor at the University of Texas LBJ School of Public Affairs.
But Dorn said the candidate had not gone too far with his attitude. "I see no evidence that he's making a leap toward arrogance," he said.
The confidence is clear throughout Obama's campaign staff. Campaign manager David Plouffe poured scorn on Clinton's chances as he discussed the stakes for the Texas and Ohio primaries.
"The Clinton campaign needs to begin winning big states with big margins to have any hope," he told reporters in a conference call on Friday. "They are going to fail on that measure and fail miserably."
Strategist David Axelrod said the staff was pleased but focused.
"We're happy with the way that things are going but we're also aware that we have a great challenge ahead," he said.
"We've won some primaries, some caucuses. We've not won the nomination and we have to battle for that nomination and we know there's another fight behind that that's going to be very, very challenging."
Obama said recently he would be facing pressure to drop out if he had lost as many contests as Clinton has.
"Look, I'm the challenger. I'm the upstart. I'm the insurgent," he said. "She's the champ. She's part of the Democratic network in Washington and, you know, if you're the titleholder, then you don't lose it on points. You've got to be knocked out."
(Editing by Bill Trott)
(To read more about the U.S. political campaign, visit Reuters "Tales from the Trail: 2008" online at blogs.reuters.com/trail08/)