(CNN) -- The caravan is like Ebola.

The caravan is like death panels.

Let me explain what I mean.

In the past few days, many members of the media have pointed out a sudden change in President Trump's priorities. In the closing week of the midterm campaign, Trump mentioned the migrants traveling through Mexico toward the US southern border more than 60 times. He portrayed the migrants as an imminent threat and parroted Fox's use of the word "invasion" to describe the travelers. He pushed to keep the migrants in the news.

And yet Trump has only used the word "caravan" once since election day, and it was almost in passing, at a news conference the next day. The migrants are still heading north, but you'd barely know it from Trump's behavior.

So here's the thing: Trump's predecessor, Barack Obama, predicted this would happen.

"Right before the election, they try to scare the heck out of you," Obama said in a blunt critique of the GOP on October 26. "And then the election comes, and suddenly the problem is magically gone. Everything's great. 'I'm sorry, what did we say?'"

This, Obama said, "is what happened in 2010, this is what happened in 2012, what happened in 2014, just over and over and over again, they'll just run these same stories and then after the election, suddenly they're not interested anymore."

He brought up three past examples and used each one to criticize Republican messaging techniques.

-- In the run-up to the 2010 midterms, the recent passage of Obamacare fueled rage on the right. "They said government bureaucrats are going to kill your granny. Remember? 'Death panels.' Then right after the election, what death panels? Didn't exist," Obama said.

-- In the run-up to the 2014 midterms, the Ebola outbreak was a big story. At the time, then-businessman Trump argued that Ebola patients should not be allowed to enter the US for treatment. Obama described the faux panic this way: "Ebola's going to kill everybody. Gotta keep everybody out."

-- In 2016, he said, "it was Hillary's emails. Terrible! That's all you could read about, emails, emails, oh man, threatening our national security, irresponsible. They didn't actually care about it because if they did, they'd be up in arms right now about the fact that the Chinese are listening to our President's unsecured iPhone, which he leaves in his golf cart! What happened? What happened? You know, this was a national security threat. You remember?"

So that was Obama's argument: Republicans shamelessly hype certain stories for electoral advantage.

His comments doubled as a critique of the media, too. And they're interesting to re-read in light of the midterm results.

The "caravan" received daily news coverage when the migrants set out on foot in Honduras in October. Some journalists, in retrospect, thought the amount of attention was excessive, given how far away the migrants were from the US border. Some news outlets produced excellent and nuanced stories about the travelers and their reasons for fleeing Central America. But other outlets, particularly on the pro-Trump side, portrayed the travelers as a threat and sowed conspiracy theories about who was behind the journey.

As election day neared, many news outlets pulled back on the daily coverage. But Trump talked about the topic practically every day, either on Twitter, in interviews or at rallies. Many of his media boosters on Fox News did the same. So the topic hung in the air.

Obama jabbed Fox in his October 26 speech.

"I mean, now there's a certain news station that they just, their business is ramping up these scare tactics, that's what they do," he said.

But other outlets, he argued, are part of the problem too. They amplify "lies over and over again even when they don't intend to," simply by covering what Republicans are talking about, he said.

Obama isn't the only Democrat making this case. Media Matters, a liberal media monitoring group, tallied up all of the caravan-related stories in The New York Times and The Washington Post, and found that coverage of the topic "plummeted" after the midterms.

Media Matters called out Fox News, CNN and MSNBC too, saying the cable news channels "focused their attention on the subject Trump wanted to discuss. And in the same manner as the Post and the Times, the volume of their reporting has dropped substantially since the election."

Fox's coverage was the most intense -- particularly on its pro-Trump talk shows like "Hannity" and "Fox & Friends."

CNN's John Avlon reported on "New Day" that the "caravan" was mentioned on Fox 733 times in the seven days preceding the election, and only 126 times in the seven days since.

"The president was simply trying to stoke the fires of fear and anger to motivate his base before the election," Avlon said.

Meanwhile, many of the migrants are still walking toward the US border. More than 6,000 people their left temporary shelter at a stadium in Mexico City and headed north on Saturday, according to Mexican state-run media.

A small group that broke off from the main group of migrants and traveled north by bus arrived at the border earlier this week. This became big news on Fox's talk shows, some of which ran new banners proclaiming that the migrants moving north constitutes a "CRISIS."

But it's no longer a lead story in most places. Just as Obama predicted.