"By admitting he is very interested in running, appearing at multiple events showcasing potential presidential candidates, and making repeated visits to early primary states, Gov. Walker has made clear he is testing the waters for a presidential race. OARs activities to date indicate it is operating as Gov. Walkers exploratory committee. Gov. Walker has made plain he is using OAR to decide whether the run for president, and he is raising funds for OAR that are being used to pay for his travel and his staff of political advisors. As a result, any contributions he or OAR uses testing the waters may not exceed the Acts limits or come from a corporation.
Gov. Walker and OAR violated the Act by accepting a $25,000 contribution from Mr. Hubbard far in excess of the prescribed limits. Gov. Walker and OAR further violated the Act by accepting a $100,000 contribution from an unknown contributor. OAR also accepts corporate contributions, and while it is not clear if either of these contributions or any other contributions to OAR came from corporations, if they did, those contributions also would violate the Act."
http://americandemocracy.org/adlf-calls-for-investigation-into-potential-walker-violation-of-federal-law/