Spending spikes in final weeks of Senate races

Top 5 Senate races, outside spending by week

Top 10 Senate races, outside spending by week and by party

Source/Methodology: Center for Public Integrity analysis of Federal Election Commission data collected by the Sunlight Foundation and the Center for Responsive Politics. Totals include 2012 general election spending only. Data includes reports filed with the FEC as of 10 a.m. Nov. 6.

Graphics by Andrea Fuller