Party committee receipts and lobbyist bundles
| Rank | Name | Amount from lobbyist-bundlers | Total receipts |
| 1 | Democratic Senatorial Campaign Committee | $882,000 | $13.7 million |
| 2 | Democratic Congressional Campaign Committee | $18,500 | $22.6 million |
| 3 | National Republican Congressional Committee | N/A | $17.5 million |
| 4 | National Republican Senatorial Committee | N/A | $6.9 million |
Source: Center for Public Integrity analysis of Federal Election Commission filings. Total receipts reflect money raised between Jan. 1, 2013, and March 31, 2013.