Dark money is flowing in the Sunshine State and eroding the ability of Floridians to determine who spends big money to influence public policy. A new report indicates the number of dark money groups in Florida — so-called social welfare nonprofits that do not have to disclose their contributors or detail their political expenditures — has more than doubled in recent years. This is the sort of secrecy that breeds corruption, and voters should insist on national reforms that restore transparency as the antidote to such a serious threat to democracy.The report by MapLight, a nonpartisan research organization, confirms the influence of dark money extends far beyond Washington and into Florida. Mary Ellen Klas of the Times/Herald Tallahassee Bureau reports that MapLight's Florida data show the number of dark money groups in the state has risen from 67 to 155 since a pivotal 2010 U.S. Supreme Court decision. These groups raised more than $13 million in Florida from unnamed sources in their last reported tax year, and they represent interests ranging from nursing home operators to eye doctors to activists for gay and lesbian rights — to interests that are not clear at all.Much of the blame for this mess rests with the U.S. Supreme Court. The 2010 Citizens United decision opened the floodgates for corporations and labor unions to spend unlimited amounts of untraceable money on political speech. One terrible result is the proliferation of super political action committees, which can accept unlimited contributions but at least have to disclose their donors. Even worse is the spread of social welfare nonprofits, which exploit the court decision and tax law to accept unlimited, secret donations spent on political speech. As long as they claim they are not spending more than 49 percent of their total contributions on efforts to influence voters, they can get away with it.Here's one example of how this legalized money laundering works. As Klas reported, the group "Our Florida Promise" created by nursing home owners and operators raised more than $280,000 in untraceable sources in its last reported tax year while raising political money through more traditional avenues that has to be publicly disclosed. Or take the Florida Optometry Eye Health Fund, a nonprofit that raised almost $800,000 from unnamed sources and then transferred $200,000 to its political committee. Or take Florida For Care, another group pushing for voters to approve a constitutional amendment allowing medical marijuana that raised more than $189,000 from unnamed sources.The campaign finance laws designed to allow citizens to see who gave how much money to whom and for what are in shreds. Why give money directly to political candidates when there are limits on contributions and the donors have to be disclosed? Just write one big check to a super PAC, or write a big check to a social welfare organization that doesn't even have to disclose the donation. No need to write a check to a political committee advocating for a candidate or a change in state law or a constitutional amendment. Send the check to a social welfare organization that does not have to disclose its donors, and it can spend the money itself or bundle it in a big money transfer to a super PAC. The Center for Responsive Politics reported this week that a social welfare group supporting Sen. Marco Rubio's presidential bid received $13.5 million from one unnamed donor.This is not just a Washington issue. This is a Florida issue as well. As the political campaigns heat up, voters should be demanding solutions from candidates for president, Florida's open U.S. Senate seat and U.S. House seats. If there is no way to reduce the special interest money in politics, there ought to at least be a way to require the sources of all that cash to be promptly identified.