DAVID GREENE, HOST:
The first presidential primaries are almost here, but let's step back for a moment. Remember last spring - the start of campaign season? The buzz was all about super PACs - how they would be more involved - for example, picking up the hefty tab for some TV advertising. Well, here we are today, and the leading Republican candidate doesn't even have a super PAC. So, NPR's Peter Overby, what happened?
PETER OVERBY, BYLINE: That leading candidate, of course, is Donald Trump. Here he is last month at Hilton Head, S.C.
(SOUNDBITE OF SPEECH)
DONALD TRUMP: You can't turn on this television without these commercials on Fox. Every two minutes, it's a commercial on Trump.
OVERBY: Trump just recently started buying TV himself. All of the other candidates have been on the air for months, and mostly the ads are coming from supposedly independent super PACs.
(SOUNDBITE OF POLITICAL AD)
TED CRUZ: And we need to take power out of Washington and back to we, the people.
OVERBY: Ted Cruz...
(SOUNDBITE OF POLITICAL AD)
CHRIS CHRISTIE: No one in this race has been more tested than I've been.
OVERBY: ...Chris Christie...
(SOUNDBITE OF POLITICAL AD)
UNIDENTIFIED MAN: Jeb will destroy ISIS and keep America safe.
OVERBY: ...And Jeb Bush, who's super PAC leads them all. Right to Rise accounts for 97 percent of Bush's TV spending and more than a third of all the TV spending by all the candidates in both parties. That's according to the media firm SMG Delta and NBC News. Super PACs are so super because they take unlimited contributions from wealthy donors - money the candidate's campaign cannot accept. But John Feehery, a veteran Republican adviser, cited Bush as an example of how super PACs don't always work.
JOHN FEEHERY: If you put all of your most creative thinkers at the super PAC - you know, Mike Murphy, for example, is at the Bush super PAC.
OVERBY: Mike Murphy is one of the Bush family's favorite strategists.
FEEHERY: That has actually kept him out of the day-to-day decision making of the campaign, which I think has hurt the Bush campaign. They really do miss his creative thinking.
OVERBY: This is just the second presidential election since super PACs became legal. In 2012, they were attack dogs. The Mitt Romney super PAC tore down Newt Gingrich in the Republican primaries. Now super PACs also do positive messages about their own candidates, but Republicans with the biggest outside spending - Bush, Christie and John Kasich - are all stuck low in the polls. Super PACs can even keep candidates afloat when the campaign money runs low, although that can't go on indefinitely.
DIANA DWYRE: It might help us understand why there's still so many people in the Republican primary.
OVERBY: Diana Dwyre is a political scientist at California State University, Chico. She said super PAC donors aren't always in sync with the voters.
DWYRE: I mean, if they were picking horses at the track, you know, they'd probably be more strategic about it than the way the some of them are picking where to throw their dollars.
OVERBY: And here's another thing. Nobody's figured out what else a super PAC can do that really helps a presidential hopeful. Bobby Jindal and Carly Fiorina had super PACs running their campaign events. The candidate was essentially a guest. Jindal dropped out in November. Fiorina's barely hanging on. The most unlikely super PAC success of 2016 may turn out to be a Democratic group from 2013 and 2014. Ready for Hillary built an email list of nearly 4 million Clinton supporters. The Clinton campaign now has that list. Democratic consultant Phil Singer said it's a big deal.
PHIL SINGER: The Ready for Hillary operation created a significant amount of data. And it might prove to be a classic model for how to go about using an outside group to propel a candidacy.
OVERBY: But Dwyre, the political scientist, said super PACs can only do so much.
DWYRE: If you're not a good candidate, if you don't have the other ingredients there, it's not going to matter whether you have a big super PAC behind you.
OVERBY: A factor that won't likely deter any White House hopeful from setting one up. Peter Overby, NPR News, Washington.