As expected, the Club for Growth announced this morning that it was making a significant financial investment in former Texas Solicitor General Ted Cruz, who is battling Lt. Gov. David Dewhurst in the Senate Republican primary runoff.

The $1.5 million buy is sizable but does not go as far in Texas as it would in other states with cheaper media markets. The runoff election is scheduled for July 31.

The 60-second radio ad  briefly mentions Cruz but then quickly shifts into a negative tone and calls Dewhurst “a moderate.”

Although Dewhurst is spending heavily on television, the club buy, along with the news that Cruz has reserved $1.6 million in television ad space through the rest of the primary runoff, means the Cruz campaign will have a serious media presence.

The winner of the runoff will most likely become the next Senator from Texas. This is an open-seat race to replace retiring Sen. Kay Bailey Hutchison (R).