There are more than two years to go before Hong Kong acquires a new Chief Executive in place of Donald Tsang Yam-kuen. But already the administration has a lame duck look as Tsang gives the impression of tiring of being criticized and anxious to retire. Meanwhile the two most evident candidates to succeed him, Chief Secretary for Administration Henry Tang and executive council convenor Leung Chun-Ying are engaged in a very public battle for leadership in the opinion polls.