Super PACs and other independent groups spent almost $1 million in Kentucky and Arkansas, the two states that held primaries on Tuesday. 

So far this year, super PACs have spent at least $16 million on congressional races, a fraction of what they've pumped into the presidential campaign. But the smaller amounts spent in congressional races have sometimes produced big results, pushing a few candidates to primary victories. So far, super PACs and other independent group have spent on 88 races.

In Kentucky the big spender was the Liberty for All super PAC,which run by a few twenty-something supporters of GOP presidential candidate Ron Paul. The super PAC provided the lion's share of the $766,000 in outside money spent in one of the state's House races, which helped bump Thomas Massie to the top of of a seven-way battle for the Republican nomination in the northern Kentucky district currently represented by retiring Rep. Geoff Davis, R-Ky. You can see the ad Liberty for All made for Massie above.

Liberty for All's chief funder, John Ramsey, started the organization in Texas to support Paul, and shifted to funding local super PACs after the the Texas congressman's chances of winning the GOP presidential nomination waned. Ramsey sees Super PACs as a grassroots-organizing tool. Massie also got support from Republican mainstay, Club for Growth.

In Arkansas, the House Majority PAC, the super PAC spinoff to elect House Democrats spent on running ads against Republican incumbents Rick Crawford in the state's 1st Congressional District and another $60,000 against Tim Griffin in the 2nd Congressional District. Both these seats lean Republican. In the Natural State's 3rd Congressional District, the fiscally conservative Club for Growth's nearly $10,800 contribution helped Army veteran Tom Cotton, easily defeat Beth Anne Rankin, who had the support of her former boss, ex-Arkansas Gov. Mike Huckabee. Cotton is hoping to pick up the seat currently held by retiring Democratic Rep. Mike Ross for the GOP.