It strengthened state constitutional limits, first imposed by Measure 5, on property taxes on real estate.
Proponents were upset by rising property taxes, largely caused by increasing real-estate values in the Portland area.
Furthermore, they opposed the double majority rule, arguing it gave non-voters more political power than those willing to vote.
Petitioners claimed that Measure 47 would cap the assessment of properties—the value of the property as determined by the county—to prevent taxes from being raised more than three percent annually.
Sizemore placed an argument in the Oregon voters' guide in an attempt to clarify the measure's provisions.
[3] Nonetheless, the legislature sent Measure 50 to voters the next year to clarify that the cap applied to the assessed value of the property as well.
Measure 47 enacted Oregon's "double majority" rule, which placed an additional requirement on state and local tax levies.
Since the passage of Measure 47, the double majority requirement has caused the defeat of many proposed local tax levies.
According to the League of Oregon Cities, between 1997 and 2007 of the 1,358 total tax measures on ballots in the state, 616 passed and 742 failed, and 169 of those failures resulted from the double majority rule.
In 2007, activists representing schools, the public employee union, and business interests lobbied the Oregon Legislative Assembly to scale back the requirement,[citation needed] and by June 2007 both houses of the legislature had approved House Joint Resolution 15, putting a measure before the voters on the November 2008 ballot.