By Brian Winter and Kieran Murray
SAO PAULO, June 12 (Reuters) - After years of construction delays and budget overruns, the World Cup kicks off in Brazil on Thursday under a cloud of discontent at home even as happy foreign fans pour in for the tournament.
Brazil's national team hosts Croatia in the opening match at a newly built stadium in Sao Paulo whose cost and late delivery came to embody the troubled World Cup preparations.
Brazil is seen by many fans around the world as the spiritual home of soccer and hundreds of thousands will descend on the country for the month-long tournament, but until now the enthusiasm among Brazilians has been muted.
Many are angry over the $11.3 billion spent on hosting the World Cup when basic social services are poorly financed.
Massive street demonstrations rocked the country last year and although they have faded in numbers recently, officials expect a hard core of a few hundred people to try to block traffic to the stadium on Thursday. That could cause violent clashes with police.
Brazilians say the country will rally as soon as the action starts, especially if their team justifies its billing as favorite to win the tournament for a record sixth time.
"Just wait until Brazil starts winning. Then you'll see people in the streets," said Rogerio Souza, a fan in Sao Paulo, although he warned failure would cause more discontent.
"Brazilians only count titles. No one cares about second place. If they don't win the Cup at home, you'll see the criticism rain down,"
President Dilma Rousseff dismisses complaints about the heavy spending and delays in preparing stadiums and airports, and is betting Brazil will put on a show on and off the field.
"What I'm seeing more and more is the welcome given to the teams and the happiness of the Brazilian people with our team," she said in a speech on Wednesday.
Yet the list of possible problems is long. In fact, hosting a successful World Cup may ultimately prove harder for Brazil than winning it.
The main risk, for both fans and the government, appears to be violent street demonstrations.
Protests and labor strikes are planned in the 12 host cities, including a 24-hour slowdown by some airport workers in Rio de Janeiro although the threat of a long subway strike in Sao Paulo has eased.
Some businesses in Rio, the venue for seven Cup games including the final, had boarded up windows and doors by late on Wednesday in case protests erupted.
Officials privately expressed fears that protests and traffic problems could mean some fans might still be stuck outside the Arena Corinthians in Sao Paulo when the opening match starts at 5 p.m. (2000 GMT).
The government has decreed a partial holiday for Thursday to help ease congestion. Still, a long list of VIPs including 10 heads of state and senior officials from world soccer body FIFA mean traffic will still be complicated.
The stadium itself has been a source of anxiety.
Not only was it delivered six months late at a cost of $525 million, about $150 million over budget, but because of the delays Thursday's game will be the facility's first at full capacity. That's a big no-no in the field of logistics and a violation of FIFA's normal protocol for World Cup games.
"I'm praying that nothing goes wrong," said Lizbeth Silva, a clerical worker at a Sao Paulo school. "You hear about all these problems, but you still want to root for Brazil."
The stakes for Brazil go well beyond the World Cup itself.
Rousseff is running for re-election in October, and a rough tournament would likely cause her popularity, already under duress, to fall further. Polls show she currently holds a lead of about 10 percentage points over her likely rival if the vote goes to a second round, as most expect.
Any major logistical problems and unrest could also further dent Brazil's reputation among investors, which has suffered since a decade-long economic boom fizzled under Rousseff.
At least one element is expected to cooperate on Thursday: the weather. Forecasters expect clear skies and a high of 75 degrees (24 C) - warm for the southern hemisphere winter.
Brazil's team, led by its exciting 22-year-old star striker Neymar, is heavily favored to beat Croatia.
As the tournament progresses, the fervor of foreign fans, hordes of whom have already descended upon host cities, could also help ease any tension among Brazilians themselves.
Outside Rio's Maracana stadium on Wednesday, Brazilians cheered and whistled as an SUV with a Colombian flag draped atop it stopped at a red light.
"We wouldn't miss this for the world," said the driver, adding that he and his three passengers left Colombia by road nearly three weeks ago. (Additional reporting by Paulo Prada in Rio de Janeiro and Brad Haynes and Esteban Israel in Sao Paulo; Editing by Todd Benson and Paulo Prada)