Big donors are piling cash into the campaign to support Measure 90, the November ballot measure that would end Oregon's partisan primary system.

Filings with the elections division show new contributions from Associated Oregon Industries ($50,000), Portland insurer The Standard ($25,000), Portland property magnate Greg Goodman ($15,000) and Harsch Investment Group, the Schnitzer family's property investment firm ($10,000).

Proponents of Measure 90 want to replace the current primary system with a "top-two" system in which the two leading vote getters in a primary, regardless of party affiliation, would advance to the general election. So far, the have shown strong fund-raising ability, raising $623,000 to qualify for the ballot and another $175,000 since.

The opposition campaign, the Protect Our Vote committee, has raised just $20,000 so far.