Remember when the media went ballistic over Donald Trump saying he would temporarily ban Muslims from entering America?

This time he had gone too far, and even mainstream journalists such as Tom Brokaw denounced his plan as betraying American ideals and aiding terrorist recruitment.

Now it’s the first issue of Trump’s first television commercial, hitting Iowa and New Hampshire television screens this morning as part of a $2-million-a-week campaign first reported in this space last week. The 30-second spot also says that Trump will “cut off the head” of ISIS and seize its oil, and build a wall and make Mexico pay for it.

Why does a guy who gets saturation coverage need to spend a dime on advertising? Perhaps because he doesn’t want to risk waking up after narrowly losing the Iowa caucuses to Ted Cruz and saying he should have been on the airwaves. If nothing else, advertising is an insurance policy.

But it’s hard to deny that advertising has mattered less in this campaign than in any other modern presidential contest. Marco Rubio and his PACs have spent $15 million on ads and his numbers barely moved. Jeb Bush and his PACs have dumped $35 million on ads and he’s still in single digits.

Trump’s initial ad isn’t exactly packed with new information. He triples down on his plan to temporarily bar Muslims from entering the United States—you know, the proposal that many in the mainstream media believed would seriously wound his campaign. 

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Sometimes a first ad introduces a candidate; Trump obviously doesn’t need that. Sometimes they show a softer side, with family photos: Trump’s not interested in that either. He’s sticking with what brung him to the dance, hard-edged rhetoric on terrorism and illegal immigration.

And by the way, does anyone really care about Politifact’s “Pants on Fire” charge that the ad used footage from Africa to illustrate the Mexican border problem? Production companies make these kinds of mistakes all the time.

Trump, of course, got quite a bump in free coverage yesterday as television networks kept showing the ads. Cruz, whose Super PAC also released a $1-million terrorism ad with scary music—with a punchline of Marco Rubio talking about fantasy football, ergo he must not care about terror—got much less media attention.

In an era when we’re inundated with messages from Facebook, Instagram, Twitter, YouTube and Snapchat, the old-fashioned 30-second ad doesn’t carry as much weight. But even in its heyday, viewers were skeptical of candidates making claims and promises. What tended to work was negative ads, as Mitt Romney demonstrated, because people were more likely to believe bad information about a rival. 

But in a multi-candidate field, there is often a backlash against the attacker as well. And there is a reason that only Super PACs associated with Bush and John Kasich have gone after Trump, and then relatively briefly. I quoted Trump sources last week as saying that they would hit back at negative spots many times harder, given that The Donald is funding his own campaign. And even non-advertising attacks on Trump have tended to backfire.

With Iowa voting four weeks from today and New Hampshire the following week, there will be a blizzard of charges and countercharges that will inundate television viewers in those states. The media have a special responsibility to critique and fact-check these spots rather than simply re-airing them. But at a time when public distrust of journalists is so high, that may be a tall order.

Howard Kurtz is a Fox News analyst and the host of "MediaBuzz" (Sundays 11 a.m. and 5 p.m. ET). He is the author of five books and is based in Washington. Follow him at @HowardKurtz. Click here for more information on Howard Kurtz.