Most of the discussion around Ted Cruz's decisive win of the Republican nomination for Senate from Texas involves a swell of grassroots support from Tea Party activists. But conservative super PACs did their part online, including Club for Growth, FreedomWorks, and Endorse Liberty, the group founded to support Texas congressman Ron Paul in the presidential race. Anti-tax group Club for Growth appears to have been the biggest online ad spender, plunking down $432,000 on digital ads and communications in June and July, according to ClickZ's analysis of Federal Election Commission filings. In all, super PACs spent nearly $700,000 on digital ads in June and July to back Cruz and oppose his rival, Republican David Dewhurst…