Barbour, as well as fellow possible candidates Mike Huckabee and Sarah Palin, has maintained publicly that those activities do not constitute a campaign. They pay for the operations out of their own federal and state political action committees, which are not subject to the same strict donor limits as campaign committees.
"These outside-the-limit contributions present precisely the threat of political corruption that contribution limits are intended to reduce or eliminate," said Paul S. Ryan, an election law analyst with the nonpartisan Campaign Legal Center.
Federal and many state PACs have not yet submitted financial disclosures this year. Until then, it's impossible to know how much money these noncandidates have raised and spent in their informal campaigns.
As the political calendar progresses, the pressure to make things official will increase. Fox News, organizer of a Republican presidential debate on May 5, announced last week that participants must have announced an exploratory committee or presidential campaign, and must have filed papers with the FEC by April 29.
By that standard, it will be a sparse lineup for the first debate of the 2012 cycle: So far, Romney and Pawlenty would be the only major contenders to make the cut.