"Federal multi-candidate PACs are limited in the amount of money they can contribute to candidate campaigns or other organizations:
•at most $5,000 per candidate per election. Elections such as primaries, general elections and special elections are counted separately. •at most $15,000 per political party per year. •at most $5,000 per PAC per year."
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However...The FR PAC can spend as much as it wants here:
"Contributions by individuals to federal PACs are limited to $5,000 per year. It is important to note, however, that as a result of the United States Court of Appeals for the District of Columbia Circuit decision in SpeechNow.org v. FEC, PACs which make only "independent expenditures" (that is, advertisements or other spending that calls for the election or defeat of a federal candidate but which is not coordinated with a federal candidate or political party) are not bound by this contribution limit."
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"Super PACs
The 2010 election marks the rise of a new political committee, dubbed "super PACs," and officially known as "independent-expenditure only committees," which can raise unlimited sums from corporations, unions and other groups, as well as wealthy individuals. [6] The super PACs were made possible by two court rulings, including one early this year by the Supreme Court, that lifted many spending and contribution limits. The groups can also mount the kind of direct attacks on candidates that were not allowed in the past. [7] Super PACs are not allowed to coordinate directly with candidates or political parties and must disclose their donors."
And from the SCOTUS Citizen United case:
"Justice Anthony M. Kennedy, writing for the majority in Citizens United, said that “independent expenditures, including those made by corporations, do not give rise to corruption or the appearance of corruption.” "
Good thing McCain/Feingold was eviscerated. :-)