Given Taft's death in 1953, I often see this scenario proposed as a way to install some other Republican as President of the United States. Richard Nixon, Joe McCarthy, Douglas MacArthur...
Willliam Knowland would have been in many respects an ideal running mate for Taft: geographical balance (from an important state distant from Taft's Ohio); relatively young; a veteran; ideologically compatible with Taft but also acceptable to internationalist Republicans as well. (Though Knowland was sometimes labeled an "Asia-firster" for his strong support of Chiang Kai-shek, he rightly noted that this was unfair; he had supported the Marshall Plan--about which Taft was lukewarm--and the North Atlantic Treaty, which Taft opposed.) In fact, a biography of Knowland is entitled One Step From the White House: The Rise and Fall of Senator William F. Knowland. http://www.h-net.org/reviews/showrev.php?id=2567 The point being of course that if Knowland had deserted Warren for Taft, and Taft had won the nomination and general election with Knowland as his running mate, and Taft had died on schedule from cancer, Knowland would become president in 1953.