OTTAWA—Peter MacKay is the ultimate political strategist. He was one-half of the team that united the Conservative and Reform parties, after promising never to do so in writing. He went on to join the cabinet of his negotiating partner and future boss, prime minister Stephen Harper. The two were not exactly bosom buddies. But they made political hay together for nine years until MacKay wisely read the tea leaves before the last election and decided not to run.