Which is why we must remove the political realm from transit planning, projects of this magnitude simply cannot be built within a politician's 4 year term.
We need to return to operational subsidies of transit agencies and leave them (hopefully transit agencies are better at transit planning than a politician) to plan the growth and expansion of the network.
Unfortunately that wouldn't really rid us of political meddling. As long as politicians sit on these boards, they will be subject to the political tides. If politicians aren't on these boards, you can get your ass some Conservative group is going to stand up and say "there's no public accountability on this board, we need to abolish them!". Let's face it, people are stupid, and politicians cater to this. They refuse to listen to the difference between an educated "no, that won't work, maybe you should try something else" and a jo-schmo whos up in arms about a project he has no comprehension of (ie "this project is a waste of taxpayer dollars, I won't stand for it!"). There needs to be a greater distinction made between the opinion of a university graduate and the opinion of a tea party member (just using them as an example, but pretty much any NIMBY group will work). They may be equal in democracy, but they are not equal in intelligence (on average).