Most of the millions of dollars raised in the Missouri governor's race would be banned under proposed campaign contribution limits.
A measure on the Nov. 8 ballot would limit donations to candidates to $2,600 per election.
An Associated Press analysis found close to $16.5 million of Republican gubernatorial candidate Eric Greitens' fundraising, or about 95 percent, was in donations of more than $2,600.
Democratic candidate Attorney General Chris Koster received $17.8 million worth of checks of more than $2,600. That's about 80 percent of what he's raised this election.
Missouri's previous campaign contribution limits were repealed in 2008. Since then, some donors have routinely given five- and six-figure checks.
Under the proposed constitutional amendment, donors also couldn't give more than 25,000 dollars to political parties each primary and general election.