The National Republican Senatorial Committee raised $12.9 million in September, falling short of the $15.6 million the Democratic Senatorial Campaign Committee raised during the same period.

The DSCC also led the NRSC for the three-month quarter, bringing in $29.2 million to the NRSC's $25 million.

The NRSC has $23.1 million for its final election push, short of the DSCC's $27 million. Both sides have already been spending heavily on ads and have seen their cash on hand shrink, with the NRSC dipping from $28.9 million at the end of September and the DSCC dipping from $31 million.

The NRSC has lagged behind the DSCC most months this year. It's typical for the party in power to raise more money, so the DSCC's edge is no shock.

While the DSCC will have the edge in the closing days of the campaign — and many of their candidates have more money to spend on the races — GOP outside groups are outspending their Democratic counterparts, so overall it's unclear which side will spend more on the competitive races which will determine control of the Senate. The GOP needs to pick up four seats to wrest control of the chamber if President Obama wins, and that looks a lot less likely today than it did a few months ago.