By DAVID HACKETT david.hackett@heraldtribune.com Like most major donors to Section 527 organizations, Sarasota's Frank Brunckhorst prefers to let his money do the talking. Brunckhorst, 42, the chairman of Boar's Head Provisions, one of the nation's leading purveyors of deli products, has given more than $900,000 to Democratic causes in the past year. Brunckhorst's emergence as one of the Democrats' money men has surprised local and national leaders from both parties, who said they had never heard of him until he started writing checks for as much as $500,000. "This guy wasn't on any of our radar screens before this year,"...