While ballots are still being counted in the state of Florida, a senior adviser for Mitt Romney's presidential campaign told the Miami Herald on Thursday that they are effectively conceding the Sunshine State and its 29 electoral votes to President Barack Obama.

"The numbers in Florida show this was winnable," Brett Doster said in a statement to the paper. "We thought based on our polling and range of organization that we had done what we needed to win. Obviously, we didn't, and for that I and every other operative in Florida has a sick feeling that we left something on the table. I can assure you this won't happen again."

Florida would give the president a total of 332 electoral votes. Romney would finish with 206.

According to state officials, Obama leads Romney 49.9 percent (or 4,180,697 votes) to 49.24 percent (or 4,124,865 votes)—a margin of 55,832 votes—with more than 97 percent of the vote counted. If the final margin is within a half percentage point, there would be an automatic recount.

[Related: Gore on long Florida voter lines: 'Disgrace,' 'un-American']

Romney conceded the election to Obama early Wednesday.

Earlier Thursday, Jim Messina, the president's campaign manager, said during a conference call with reporters that they expected Obama would be named "the official winner in Florida later today." Saturday is the deadline for counties to file their preliminary results with the state.

The final tally is expected to be certified on Nov. 20.