The Florida Marlins will make their final pitch for approval of their $634 million stadium today, appearing before Miami-Dade County commissioners in their last at-bat for political backing of a permanent home in the Little Havana neighborhood. Commissioners have a series of votes, including one on the financing plan for the $634 million Little Havana ballpark and parking sites. Miami commissioners cemented their end of the deal with a narrow 3-2 vote Thursday. The commissioners could put the county on the hook for the greatest share of the financing plan, about $359 million, for the 37,000-seat, retractable roof ballpark on the site of the former Orange Bowl. Most of the funding would come from tourist tax dollars.