A three-quarters majority of the 32 owners is required on the first ballot Tuesday. If neither city gets that, then a simple majority wins on the next ballot.
The loser in the 2016 bidding will face Houston for the 2017 Super Bowl. Houston hosted the 2004 game.
Texans owner Bob McNair is cautious about his city's chances, even with South Florida's political and financial struggles.
"Certainly what happened doesn't help Miami's bid. There's no doubt about that," McNair said. "But that doesn't say that the owners couldn't decide to still go to Miami."
For years, it was thought the NFL would seek to stage the 50th Super Bowl in Los Angeles, where the first one was played (but did not sell out) on Jan. 15, 1967. But with no franchise in LA and no suitable stadium projects approved, that hope disappeared.
Next Feb. 2, the game goes outdoors in a cold-weather site for the first time, at MetLife Stadium in the New Jersey Meadowlands. If that gamble pays off for the NFL, look for other cities in similar climates — Washington, Baltimore, Philadelphia, Chicago, Denver — to bid for future Super Bowls.
The league also has expressed great satisfaction with how Indianapolis handled the big game in 2012. New Orleans is a regular bidder, and Commissioner Roger Goodell has said the power outage during last year's game will not impact voting on the Big Easy hosting another Super Bowl.
The 2015 game will be played in the Phoenix area.
AP Sports Writers Janie McCauley and Steven Wine contributed to this story.