How many letters does the top answer for “what candidate won the 2012 us presidential election” have?

The most common answer is barack (6 letters).

Crossword clue: what candidate won the 2012 us presidential election

2 answers found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

barack 6 letters otdb

obama 5 letters otdb

44th President of the United States; first African-American President