Corporations are prohibited by law from contributing
directly to a candidate.
The companies may contribute to political action committees, which then support candidates.
Their employees may contribute individually, of course.
So back in 2008 when Obama said he would never accept a contribution from a corporation, he was telling the truth.
But it's also true that he received more contributions from British Petroleum
indirectly in spite of the maze of campaign finance laws.
Follow up question: Which company's drilling operation in the Gulf of Mexico was exempted from a detailed
Department of the Interior environmental-impact analysis in 2009?
http://seattletimes.nwsource.com/html/nationworld/2011780029_oilrules05.html