Most campaign commercials feature grainy newsreels, press clippings, and a candidate speaking forcefully from a podium or directly into the camera. But last week, before Democrats in the state gathered to caucus, Nevadans saw something different: A commercial titled “Brave,” in which Hillary Clinton speaks softly and emotionally to a little girl who is crying about the prospect of her undocumented parents being deported. On Sunday, Clinton campaign advisers told Politico that “Brave” was the game-changer that had turned the tide for their candidate in the final days before the Nevada Caucus, where she’d been in danger of losing the crucial Latino vote to Bernie Sanders. They had blanketed the Nevada airwaves with the ad in the three days leading up to the caucuses and pushed it out online, propelling Clinton from a virtual tie earlier in the week to a comfortable win on Saturday night.

Signal… Candidates want to believe that there’s a “silver bullet” ad out there that can singlehandedly turn things in their favor, and they’ll spend millions searching for one &mdash: largely in vain, as Jeb Bush and Marco Rubio can attest. — Laura Reston

Ads like “Brave,” which the Clinton campaign is now airing in Colorado prior to its Super Tuesday caucus, are the white whales of American politics. Political strategists can go their whole careers without creating an ad that singlehandedly changes the course of an election. “The silver bullet ad: Every candidate believes in it, and every political consultant cringes when they hear it,” says Jim Duffy, a media strategist at the prominent Democratic consulting firm Putnam Partners.

In his 32 years making campaign ads for candidates from Blanche Lincoln and Roy Barnes, Duffy has worked on just one, nearly three decades ago: a commercial in the 1987 Louisiana gubernatorial race that propelled dark horse Buddy Roemer from fifth to victory in a single month. “We needed a hot message, but a cool candidate,” Duffy told me. He eventually produced a commercial called “Angry.” It was a harsh condemnation of politics as usual in Louisiana. But with his crisp suit and a light blue background, Roemer still managed to look calm and collected. The contrast was powerful. Today, railing against the political process is a common political tactic. But in the ‘80s, “it was radical,” Duffy said. “I have never seen a spot move people like that one did.” Money started pouring in and Roemer went from fifth place to second in two weeks, ultimately winning the election.

Attack ads are sometimes silver bullets, too. Democratic presidential nominee Michael Dukakis was already sinking in the polls when the George H.W. Bush campaign released “Tank Ride” in October 1988. But the indelible footage of the slight Massachusetts governor cruising along in a 68-ton M1A1 Abrams Main Battle Tank wearing an enormous helmet cemented the idea that Dukakis was well, a little bit of a wimp. “He looked ridiculous,” says David Schwartz, a curator at the Museum of the Moving Image. “That became how people saw him.”

Anecdotes like these explain why presidential candidates are still buying up thousands of ad slots before Super Tuesday — even when all the signs suggest that television has had little or no effect on the polls this election cycle, with the possible exception of Clinton’s Nevada campaign. Candidates want to believe that there’s a silver-bullet ad out there that can singlehandedly turn things in their favor, and they’ll spend millions searching for one — largely in vain, as most of this year’s candidates can attest.

Several factors have to align to make a regular old ad a silver bullet. The timing has to be perfect. The national news media has to pick up on the ad to give it extra oomph. And the commercial itself has to be bold. “You have to have the guts to do something different,” says Fred Davis, a Republican consultant who has crafted ads for candidates from John McCain to Carly Fiorina to John Kasich. “That’s what many people don’t have.”

The two Republican candidates who have pinned their presidential hopes on finding silver bullets in 2016 have both faced this problem. Through the South Carolina primary, when Jeb Bush finally abandoned his flagging campaign, the strategists at the Bush-affiliated Right To Rise super PAC — despite every indication that the $84 million they were spending on ads had had no effect whatsoever — still believed that they would eventually release a commercial that would click, sending Bush rocketing back to the front of the Republican pack. It never happened, and the campaign ultimately wasted more than $130 million waiting for one of its ads to take off.

In the remaining field, no candidate is relying more heavily on TV ads than Marco Rubio, whose PAC is spending almost $1.5 million on television ads in the Super Tuesday states — far more than any other candidate in the Republican field. But none of the commercials the Florida senator has released shows the kind of originality needed for a silver-bullet breakout. Rubio’s most recent ad, “Revolution,” is a perfect example: It features the candidate delivering a speech in South Carolina in which he declares, “the children of the Reagan revolution are ready to assume the mantle of leadership.” But with everyone referencing Reagan in the Republican primary, the ad does nothing to set Rubio apart from the other candidates still in the race. The script is predictable, and the photos of closed-down gas stations and Iranian hostages make a weak attempt to summon up some portentous lesson from history. The Florida senator may very well wind up wasting many millions on the slim chance of a silver bullet — just like the former Florida governor before him.

With new TV ads flooding the airwaves leading up to Super Tuesday, we analyzed the ten most notable spots from this week and listed the rest below. You can see every presidential spot that’s aired in this campaign cycle at the New Republic’s2016 Campaign Ad Archive.

THIS WEEK’S ADS:

John Kasich: “Crown”

Type: Biographical ad

Who Paid for It? New Day for America, the super PAC backing John Kasich

Reach: Aired in Vermont, Massachusetts, and Michigan as part of a six-figure ad buy

Impact: By showing Marco Rubio gilding backward and fading from the screen, this ad subtly underscores the idea that the Florida senator is somehow insubstantial. It could be an effective message: The best attack ads, after all, are supposed to cement people’s preexisting doubts about a candidate—and Rubio has long been accused of being nothing more than a pretty face.

This week’s other new ads from New Day for America: “Cratered,” “Quiet”

Read the entire original story at New Republic.