I think Jefferson would more than likely feel that a business has the right to take part in the political process when the outcome of that process will affect how that business is run. This really just circles back around to limited scope of government though. If the government is kept sufficiently limited and cannot largely affect business then corporations won't need to take part in the political process. The founding fathers were very suspect of political parties. It is interesting to consider how our political process would work if we didn't have them.