The American public favors the center. The decision to avoid the negative did not save Matt Fong from being defined by his opponent as mean-spirited. But it did cost him the election. Never say never in political battles. It is an art, not a science.
Position is defined by fear and hope.
The twin emotions of politics are fear and hope. Of the two, hope is the better choice. By offering people hope and yourself as its provider, you show your better side and maximize your potential support. But fear is a powerful and indispensable weapon. If your opponent defines you negatively enough, he will diminish your ability to offer hope.