Chinese Vice President Xi Jinping's U.S. visit this week shows he is all but certain to take over as China's next leader, but back home the competition is rough for the other top slots to run the country with him.
One contender, Bo Xilai, has been enveloped in a scandal involving unconfirmed reports of malfeasance by his former police chief. That has raised talk of a conspiracy to humiliate the flamboyant Bo and push the Chongqing city Communist Party boss out of contention.
Heavy turnover this year on the party's leading bodies and the lack of a strong leader are fueling battles for places that defy the Chinese preference for quiet backroom deals and public consensus, China experts say. Bo Xilai isn't the first, and may not be the last, to suffer attacks whose origins remain obscure even to insiders, they say.
"Sometimes in power struggles, you can't attack the person directly, so you try to undermine the person by attacking associates and family members. It's never quite clear where the attacks come from," said Bo Zhiyue, an expert on the Chinese leadership at the National University of Singapore. He is not related to the Chongqing party chief.
The Communist Party's rules on succession have never been clearly stated, a reflection of its secretive, topdown nature.
What is known is that the party will designate a new group of elite leaders this fall as part of a transition which began five years ago with the tacit designation of Xi as future party chairman and national president by his appointment to a top spot on the Politburo Standing Committee. He became the highest-ranking member who would still be short of retirement age during the next leadership turnover.
Current President Hu Jintao was dispatched to the U.S. on a similar visit shortly before taking power, so Xi's trip is widely seen as confirming his status as future leader.
Over several days in October, the party's 300 Central Committee members will discuss policy and select a Politburo _ which now stands at 25 members _ along with its all-powerful Standing Committee, seven of whose nine members are due to stand down because of an unstated retirement of about 67.
Whether the top leadership is selected by internal vote, direct appointment, or mutual agreement isn't known. While age and experience are strongly valued, raw power and forcefulness are as important as technical competence.
No strongman has emerged with enough influence to force through positions in the manner of Mao Zedong or Deng Xiaoping, who tipped Hu to take over as eventual leader back in 2003, over the head of then-president Jiang Zemin. Hu will retire this fall.
"In the past, someone strong would have stepped in to settle matters," said Ding Xueliang, a China politics expert at Hong Kong's University of Science and Technology, speaking both of the Bo Xilai affair and the succession in general. "That's all changed now."
The 80 million-member party needs to seek a balance between rival interests, said Ding and others. Presently, the leadership is dominated by hard-liners led by Hu and parliamentary boss Wu Bangguo.
They tend to favor the economy's state sector, strong suppression of dissent and alliances with other authoritarian regimes, said China expert Feng Chongyi of Australia's University of Technology in Sydney.
Xi, 58, is seen as a consensus choice defined by his pragmatism, but he also is considered to lean toward the private sector, a strong legal system, and friendships with democracies such as the U.S., Feng said.
He's also representative of the party "princelings," whose careers have been helped by their family connections to communist elders.
Li Keqiang, tipped as the next premier, is from the party's populist wing, associated with Hu's party youth wing faction but not considered a strong conservative, Feng said.
Adding to the competition, former leader Jiang is also seeking to preserve his influence through moderate candidates for leadership positions, such as Tianjin city party chief Zhang Gaoli and Public Security Minister Meng Jianzhu.
The scale of the leadership turnover and intensity of the competition make this year's succession especially challenging, China watcher Cheng Li of the business-oriented Brookings Institution in Washington wrote in a recent study.
Xi and the others who take over the party later this year _ and who will be formally promoted to their government posts next spring _ will have to deal with severe challenges such as discontented migrant workers, rapid urbanization, pollution, corruption and ethnic unrest.
There is a risk that divisions over personnel and policy could cause paralyze the new leadership's decision-making, Li said. With the economy slowing and unrest simmering in parts of the country, that could pose real dangers, he wrote. Beijing would have few tools to respond to greater unrest other than greater repression.
In recent months, anti-government violence has risen in Xinjiang and in Tibetan areas, where 20 Buddhist monks, nuns and laypeople have set themselves on fire in protests against official policies.
Although Bo Xilai's future has yet to be decided, recent events show how quickly political winds can shift in China.
Unconfirmed media reports say an investigation into abuse of power has targeted Chongqing's former top policeman Wang Lijun, who had been closely linked with Bo and oversaw a crackdown on gangs and corrupt officials on Bo's behalf.
That campaign won Bo and Wang national attention and fueled speculation Bo was angling for a Politburo Standing Committee seat. But Wang has not been heard from since he visited the U.S. consulate in the city of Chengdu more than a week ago, possibly a failed bid for asylum. The incident harms Bo by showing him as unable to control his subordinates and taints him by association with alleged abuse of power.
"The least we can say is that Bo is now in trouble, if not completely out of the running," said Ding, of Hong Kong's University of Science and Technology.