WASHINGTON – The super PAC helping Bill Nelson withstand an avalanche of money from Rick Scott has reserved $23 million in air time, a significant boost for the outspent Democrat.

Senate Majority PAC had already announced it would buy time for Nelson, but the amount was not revealed until today. The ads are to begin Oct. 2 and run through Election Day, a spokesman said.

Scott's campaign, which tracks ad spending, issued a fundraising alert off the number. "If you weren't able to donate yesterday – please reconsider. This is a significant shakeup in the race, and we need your help now more than ever," it read.

Scott and allies have already spent or reserved about $20 million.