HOUSTON -- Congressman Ron Paul is considering using $4 million left over from his failed presidential campaign to start a for-profit publishing company that would reflect his Libertarian-leaning views.

The move could test the limits of federal campaign finance rules.

Federal guidelines say the money can’t be used for personal things like vacations and mortgage payments, but it’s not clear if he could use the money for a company that would produce educational material.

Paul also has a potential gold mine in his mailing list, if he rents those names to interest groups or other campaigns.