The MA subway/bus/commuter rail system is on its death bed again. The MBTA (T to locals) has gotten little help from the state. Instead, over a decade ago, the lege loaded it with billions of debt from the Big Dig. Offsetting revenue would come from the never-ending growth of sales taxes, which never happened. Now the governor proposed a huge, expensive overhaul. Lawmakers responded with one-fourth of that, and refuse to fix their blunder. The latest fantasy is a tripling or quadrupling of fares on top of previous hikes, and far fewer T vehicles. It's veto v.override time. Can Gov. Patrick prevent the nation's oldest subway from becoming a Third-World system?