Donating to a campaign is inherently costly, and as a result, the composition of campaign donors differs from the composition of the electorate. What happens when the financial barriers to participation in campaign finance are removed? This paper analyzes Seattle's recent campaign finance reforms, where all registered voters receive four $25 vouchers to donate to candidates abiding by stricter campaign finance restrictions. Utilizing individual- and census block group-level data combined with administrative donation records, I find that those most mobilized by the availability of vouchers belong to groups already overrepresented within the donor pool. In many cases, the availability of vouchers appears to pull the donor pool even further from parity within the electorate. This finding is significant across race, income, past political participation, age, and partisanship.