The Oregon Senate has killed off the bill that would have capped campaign donations for the first time in Oregon.

But there's a question hanging over the legislative session: Will the Legislature refer a constitutional amendment to voters to make it possible to cap campaign donations in the future?

Senate Joint Resolution 18 would ask voters to amend the state constitution to allow the spending caps passed by Multnomah County voters in 2016 and by Portland voters in 2018. It would also allow future limits imposed by the Legislature or voters.

House Speaker Tina Kotek is currently "undecided" on whether she supports the constitutional referral, her spokesman Danny Moran says.

She supported the caps, which passed the House on June 6 but died June 14 in the Senate, but she hasn't decided whether to support the constitutional referral in the absence of a bill to determine what the campaign caps would looks like.

Oregon is one of just five states without caps. That's in part because the Oregon Supreme Court in 1997 ruled that such caps violated the constitution's protections for free speech.

Supporters of campaign finance reform are also pursuing a legal strategy to get the Supreme Court to weigh in on Multnomah County and Portland limits, which a Multnomah Circuit court judge has ruled are unconstitutional.

A hearing on SJR 18 is scheduled for this afternoon.