I wouldn't exactly classify a Barbur MAX line as a mega-project... not by a lot. I also highly doubt that it would cost any more (if not significantly less) than the yellow line extension down to Milwaukee (not taking inflation into account) as that requires a brand new bridge to cross the Willamette. This is one of, if not the most, needed MAX lines; it's great that Tigard is actually initiating the studies in this case.
As for whether or not this rests upon who the next president is... the election is in just over a month and it looks increasingly likely that Obama will win. Plus, there is no reason that I can see not to have the line studied... then, when the political environment is right they can move in for the kill.