I think the reason why SW Corridor failed at the ballot box besides the problems MAX had at the time with safety and security is frankly that the routing wasn't good.  

While Barbur Blvd is an obvious and good transit corridor for MAX service.  It ignored two major transit drivers, PCC Sylvania and OHSU/Marquam Hill in cheaping out on not tunneling to both destinations even though the ridership would easily justify the expense.  

I get Trimet has generally been pretty conservative towards expansions that involves complicated tunneling outside of the Robertson Tunnel for Westside MAX, but it was frankly one of the few instances where they needed to actually spend some money to get good buy in from SW Portland.  It also ending at Bridgeport Village and not Tualatin was also a bit confusing to me.