NEW : O'Donnell says she 'll win without establishment National Republicans support if it 's not offered . O'Donnell , backed by GOP , beats Rep. Mike Castle in GOP primary for GOP . Top GOP official : Tea Party will be slow to rally around O'Donnell . Americans say O'Donnell win could help them keep a Senate seat .
NEW : O'Donnell says she 'll win without establishment GOP support if it 's not offered . O'Donnell , backed by Tea Party , beats Rep. Mike Castle in GOP primary for Senate . Top GOP official : National Republicans will be slow to rally around O'Donnell . Democrats say O'Donnell win could help them keep a Senate seat .