The group’s Democratic counterpart, the Senate Majority PAC, has booked $80 million in television advertising across nine states, ads that are set to begin after Labor Day.

The Democratic PAC declined to detail its spending by state. But partial advertising data provided by a Republican source shows the Senate Majority PAC has purchased at least $4.5 million in Indiana, $2 million in Tennessee and $3.8 million in West Virginia.

Those figures are likely to grow as the Senate Majority PAC finalizes its purchases.

All told, the Republican super PAC has booked $40.3 million in television time, about half of what the Senate Majority PAC says it has reserved.

Committees buying television time do not actually have to send payment until the ads are set to run. According to the most recent campaign finance reports, the Senate Majority PAC had $29 million in the bank, more than double the $13.5 million the Senate Leadership Fund had in the bank.

The Democratic Senatorial Campaign Committee, similarly, has a big cash lead over its Republican counterpart. That group had $34 million in the bank as of the end of May, while the National Republican Senatorial Committee had $16.3 million in reserve.