The Minnesota House’s threat of a devastating 40 percent cut in Metro Transit operations in the next two years has eased back to a merely detrimental 10 percent cut. Unfortunately, that’s the best that can be said about the transit funding and governance provisions of a conference committee bill that GOP legislative majorities are taking into negotiations this week with DFL Gov. Mark Dayton.

This bill would do real and lasting harm to the Twin Cities’ ability to develop a modern mass transit system, which in turn would damage the economic vitality of the entire state. That’s the big picture that’s evidently eluding Republican legislators who say they’re blocking transit expansion for the sake of more spending on Greater Minnesota roads.

This is one state. The adequacy of economy-enhancing transportation infrastructure in every region has an impact on the whole, for good or for ill. Minnesotans understand as much, judging from the support for light-rail transit in the metro area measured by the April 24-26 Minnesota Poll. Statewide, 54 percent of those polled support building two proposed new lines, Southwest and Bottineau; just 34 percent oppose them. Only in northern Minnesota did a small majority, 52 percent, oppose spending tax dollars on those projects.

The GOP transportation bill would stop both proposed light-rail projects, jettisoning plans that have been years in the making, have won the support of local governments all along their routes and have already cost more than $225 million. The Southwest line is slated for a construction start later this year and Bottineau in 2018, and both are to begin passenger operations in 2021. Both lines are intended to serve the region for at least the next 50 years and accommodate a projected 825,000 additional Twin Cities residents by 2040.