It appears there's a question about the legality of how Multnomah County is spending motor vehicle taxes from car rentals. The money is being spent on basic services and tourism promotion, but a recent opinion by the Oregon Legislative Counsel claims the county is violating the Oregon Constitution because the money is being spent on services not related to road construction.
Multnomah County Counsel argues differently, saying, "We can spend it any way we want".
Such an absolute statement sounds dangerous to me. Read this story from The Portland Tribune for more details. There is no certainty about who is right, but if a decision goes against the county it could jeopardize the Convention Center Hotel project.