The 1972 Iowa caucuses, however, significantly altered the race for the presidential nomination. Senator George McGovern from South Dakota, initially a dark horse candidate, made a strong showing in the caucuses which gave his campaign national attention. Although Muskie won the Iowa caucuses, McGovern's campaign left Iowa with momentum. Muskie himself had never participated in a primary election campaign, and it is possible that this led to a weakening of his campaign. Muskie went on to win the New Hampshire primary, the victory was by only a small margin, and his campaign took a hit after the release of the "Canuck letter".