A columnist’s job is basically to give his considered opinion (aka shoot his mouth off) about an issue of the day and explain the rationale which led him to a particular conclusion. In the process of gathering and marshalling his own thoughts, he will inevitably examine the counter arguments that have led others to a different opinion, so as to ensure that his column is robust enough to withstand challenge. He also seeks to avoid elementary errors of fact. As has been said of Donald Trump in the ongoing circus that passes for Republican Party candidate selection "everyone is entitled to his own opinion, but not his own facts". This quotation is normally attributed to US Senator Daniel Patrick Moynihan, and is probably derived from a similar 1946 saying by financier Bernard Baruch "Every man has a right to his own opinion, but no man has a right to be wrong in his facts."
It is in this spirit that I have sought to understand the opposition to the idea of putting Hong Kong and mainland immigration controls side by side in the West Kowloon terminus of the high speed rail now under construction. One line of argument is that it is a matter of principle because such an arrangement would somehow undermine "one country, two systems". A second line is that permitting mainland officials to exercise their enforcement powers while physically within the geographic limits of Hong Kong would invite abuse. I sought a specific example of that fear from a proponent of this view so as to better grasp it. "Well," he said "For example, mainland immigration could arrest Long Hair and deport him to Beijing."
Now let’s all pause at this point and walk through the sequence of events implied by such an outcome. Leung Kwok Hung buys a ticket for (say) Guangzhou. He goes through the various procedures for security and identification on the Hong Kong side and presents himself to local immigration. Unless there are any warrants for his arrest pending (always a possibility in his case), he is allowed to depart. He then strolls along the corridor to the mainland immigration counter and presents whatever travel document he possesses that he thinks might get him access. At that point the mainland immigration officer exercises his authority and implements mainland law. Most likely he would say "I’m sorry Mr Leung, but you are not allowed to enter" (perhaps not quite as politely as that) and Leung has no option but to walk back along the corridor and re-enter Hong Kong. He might put up a fuss and struggle, in which case security might have to physically remove him, but they have accumulated plenty of experience of doing that over the years. But just suppose the mainland authorities had a less generous fate in mind for Leung, surely the one thing they could be guaranteed not to say is "You are under arrest" while Hong Kong journalists, cameras flashing, danced around nearby. On the contrary, he would be ushered to his seat on the train and then arrested at the first scheduled stop over the border. He has got himself into trouble, and at his own expense. Perfect.
Actually, having both sets of immigration under one roof before boarding is surely the only practicable solution. It is the kind of pragmatic arrangement Hong Kong used to be famous for before everything got politicised. Stopping at Shenzhen while everybody gets off and goes through a separate procedure would defeat the whole purpose of building a high speed through train. And many stations further north do not have immigration facilities. Processing people on the train itself might in theory be possible but would require a lot of staff working quickly, and raises problems of its own. And anyway, if a person were to be barred from entry, wouldn’t it be better to find out in West Kowloon rather than in Guangzhou? The facts, the practicalities, all point to co-location.
Which leaves us with the point of principle. Here I struggle even harder to understand the opposition. Having two different sets of immigration staff, side by side, wearing different uniforms, applying different laws under the same roof is proof positive that two systems are in play. I think the principle actually being applied here is that if the government of C Y Leung proposes something, it has to be opposed for opposition’s sake. I’m sorry, but that’s not good enough.