Bingo. They have to demonstrate to their constituents that they threw everything at the wall to try and kill it. Notice how a few bullet points down from the "safety" consideration they also just outright say they hate rails. Rails indicate investment in urban areas, and investment in urban areas signals to their constituents that there hasn't been a sufficient transfer of tax revenue from urban donor counties to rural recipient counties.
They of course understand that this won't work. But they're going to make people vote against it, or make Dayton veto it, so that in the fall Pawlenty can talk about how the DFL killed small-government reforms in favor of "unelected bureaucrats building billion-dollar trains." And honestly, stirring up outstate and exurban resentment is probably the only effective tactic they'll have given the national environment right now.