Maryland Democrat Rep. Chris Van Hollen played a bait-and-switch in a speech this week, invoking Republican support for candidate disclosure to argue that they should also support his efforts to force disclosure of donors to nonprofit groups.

Van Hollen accused some skeptics of his DISCLOSE Act (better understood as "Democratic Incumbents Seeking to Contain Losses by Outlawing Speech in Elections Act") of going back on the principles they once stood for. In reality, he and other advocates of disclosure have moved the goalposts.

The need for disclosure long enjoyed broad political consensus, particularly compared to other issues in campaign finance.

Current law reflects that consensus by generally requiring disclosure of spending that advocates the election or defeat of a candidate. As a result, candidates, parties, PACs, and super PACs disclose contributions and expenditures.

Similarly, other groups, such as 501(c)(4) social welfare organizations, must disclose expenditures and any contributions they receive for the purpose of advocating the election or defeat of candidates.

Van Hollen trumpets past Republican support for disclosure by often touting the eight Supreme Court Justices who upheld disclosure in Citizens United, but the court specifically upheld only disclosure of support for candidates.

The DISCLOSE Act and ongoing IRS efforts to restrict 501(c)(4) activity, however, mandate an entirely different type of disclosure, where the traditional justifications don’t apply.

The primary purpose of disclosure is to allow citizens to monitor potentially corrupting relationships between public officials and the private interests with which they associate.

Disclosure of donors to nonprofit groups, on the other hand, tells us nothing about what public officials have been doing.

Instead, this kind of disclosure is designed to allow government and fellow citizens to monitor our beliefs, opening up members of these groups to discrimination and harassment by their community and employers.

This is a reversal, not an extension, of the principle of transparent politics.

Disclosure of political spending is unique because it can provide context for voters to evaluate the legitimacy of messages they hear on the campaign trail.

Research casts doubt on whether this actually happens, but disclosing donors to nonprofits would not have the same effect anyway.

A contribution to a candidate or super PAC is a fairly clear sign of support for that candidate or super PAC’s endorsed candidate, but not so for contributions to groups who primarily work on issues.

Donors may be supporting an organization’s primary purpose without endorsing, or even being aware of, the small portion of its activities that are political.

Disclosing these contributions actually makes it harder for voters to figure out who is supporting what by cluttering up disclosure data with junk.

We should always bear in mind that disclosure has a price. Van Hollen is contradicted by Supreme Court precedent when he claims that his DISCLOSE Act would not harm freedom of expression in any way.

The court has recognized since the civil rights cases of the 1950s that disclosure of donors to nonprofit groups creates a chilling effect on speech and association. Given the meager benefits in disclosing donors to nonprofits, the cost is hard to justify.

The vast majority of money in politics is fully disclosed already. According to the FEC, over $7 billion was spent on federal races in 2012. Only $311 million of that – 4.3% – was by groups that do not disclose donors.

There are serious costs to expanding disclosure even further, to even more groups. Van Hollen needs to take concerns about and the costs of more disclosure seriously if he wants bipartisan reform.

Luke Wachob is the McWethy Fellow at the Center for Competitive Politics.