I don’t think “Obama is a centrist”, nor any conventional superficial political discussion comes anywhere near describing the actual decision-making process involved.
At best, I think maybe Obama chooses to delay stating outright opposition to the TPP for tactical reasons, waiting for the right level of public & media attention. It reminds me of how he didn’t seem to oppose the Keystone XL pipeline until near the end of the process. Except in this case there was the weird comment he made against Elizabeth Warren’s opposition to it.
However, I think even though Obama is clearly intelligent, I think that probably his actions and words are mainly determined by others. I’d say that for every US president since at least Gerald Ford, one or more groups/organizations beyond the president’s advisors and his political party leaders are actually making almost all of the decisions and policies, and their agendas largely do not resemble the apparent person of the president, nor his political party, nor the US government, except as is necessary to remain seemingly consistent with those stories about why things happen, whose main purpose is to form a convenient story and distraction from what’s really going on.
Which is, that most of the wealth on the planet is held, and practically all of it controlled, by one group of interrelated banks and corporations, not to mention the systems of ideas that go unquestioned and determine what people do, thought of as “economics” or “that’s the way the world works”.
The TPP is evidently something that power base wants, and they have more than enough influence over our politicians and ownership of our media to pretty blatantly attempt to bypass and ignore due political process to pass an international agreement that our laws can’t protect our environment from corporations, and that corporations should be able to sue people from impeding corporations’ right to capitalize hand over fist in any way they want to.
The biggest mystery to me, is why the corporate power base is still obsessed with increasing its domination over the money game, when they’ve already basically won the Monopoly game they’re playing and own the Earth for all purposes, yet they’re still acting as if they’re happy to destroy the Earth.
My best guess is that these people are so deep in their perverted ideas and warped world view, that they can’t perceive that’s what they’re doing.