James Antle writes in a column at the Washington Examiner website that the super PAC hasn’t turned out to be as helpful for some candidates as they might have hoped.

Unlike the formal presidential campaigns, super PACs can raise bottomless amounts of money and there is no cap on individual contributions. They can’t give money directly to the candidate they support, but they can buy ads favorable to them or critical of their opponents.

Super PACs have already raised a lot of money this cycle and most serious candidates not named Bernie Sanders are heavily reliant on them. By the end of June, just 58 big donors were responsible for $40 million in contributions, some 40 percent of these groups’ total haul.

Yet the vast sums raised by Jeb Bush’s super PAC didn’t scare many other Republicans out of the race. The GOP field eventually swelled to 17 well-known candidates and debate organizers are still struggling to find room on the stage even now that people have started dropping out.

In 2012, super PACs helped Rick Santorum and Newt Gingrich stay in the race longer than they otherwise could have. The Republican National Committee complained in its post-election autopsy that these groups were propping up weak candidates to the detriment of the eventual nominee.

That didn’t work for Rick Perry this year. He had hoped his super PAC would keep him afloat after his campaign went broke. Scott Walker also had an early exit, even though his super PAC was reportedly on track to raise as much as $40 million. Meanwhile, front-runner Donald Trump boasts about how little he needs super PACs (though he does have one).