TAMPA, Fla. -- President Obama appears on pace to defeat GOP challenger Mitt Romney in Hillsborough County, which has a long history of correctly picking presidential winners.

With 346 of 347 precincts reporting, Obama held a solid 52.6 percent to 46.2 percent lead over Romney, with 276,504 votes to Romney's 242,609, according to unofficial results from the Hillsborough County Supervisor of Elections office. Those results, if they held, would be slightly smaller than the margin by which Obama beat Sen. John McCain in the county four years ago. It also would mean that Obama managed to carry Hillsborough – as well as nearby Pinellas County -- despite the fact that the GOP held its national convention in Tampa this summer.

Hillsborough long has maintained a reputation as a reliable bellwether in a critical swing state. It is the only one of the state's 67 counties that twice voted for George W. Bush and also backed Obama in 2008. In fact, Hillsborough has the distinction of voting for the victorious presidential candidate in every election cycle since 1960, with the exception of backing incumbent President George H.W. Bush in 1992, when Bill Clinton won the White House. 

An old maxim in this state's political circles: "As Hillsborough goes, so goes Florida." That certainly could prove true once again in 2012, but it remained far from a certainty deep into Tuesday night. Voting problems in South Florida meant that hundreds of voters remained in line to vote well after polls had closed. Late returns continued to trickle in from the Panhandle, traditionally a Republican stronghold. After 10 p.m., the race remained razor-thin statewide and too close to call.