Two hours into Sunday night’s football game between the New England Patriots and the Green Bay Packers, NBC aired a new version of a widely repudiated campaign ad from President Donald Trump. The 30-second spot, which featured the image of an unauthorized immigrant cop killer, urged viewers to vote Republican to stop an “invasion” of impoverished Central American migrants walking through Mexico toward the U.S.

It was the closing pitch for an administration that spent the week before the midterm elections fabricating an immigration crisis, then blaming Democrats for it.

ASSOCIATED PRESS President Donald Trump described a caravan of Central American migrants as an "invasion" during a press conference at the White House on Nov. 1.

Almost every day last week, the White House thrust immigration to the center of national politics. The Pentagon announced plans to dispatch some 5,200 troops to the border with Mexico. Trump said he planned to eliminate the constitutional guarantee of birthright citizenship by executive fiat. He announced a coming plan to bar migrants who cross illegally from claiming asylum and to detain them indefinitely in tent cities. To hear him speak at a press conference on Thursday, it would appear the United States faces an onslaught of illegal immigration.

None of this reflects reality. For the last eight years, arrests for illegal border crossing have been at their lowest levels since the 1970s.

But it does jibe with the strategy of a president who propelled himself to the White House by making specious immigration claims. Facing an election cycle that imperils the Republican majority in the House of Representatives, the president’s message is clear: Voters should blame Democrats for a nonexistent catastrophe at the border.

The ad — which NBC abandoned, along with Fox and Facebook, after a major backlash — is part of Trump’s strategy to drum up fears of the caravan among his base. CNN declined to air it, calling it “racist.”

It’s also flatly false.

Luis Bracamontes, the unauthorized immigrant in Trump’s ad, was convicted in 2014 for killing two Sacramento police officers and has nothing to do with the caravan.

The original version of the ad that Trump posted to Twitter was even more blatantly dishonest. After showing clips of a deranged Bracamontes ranting in court about how he would escape and kill others, it claimed that Democrats let him into the country and that they let him stay. It then it cuts to video of the caravan, giving the impression that it’s composed of similar fiends.

In fact, no one let Bracamontes in. He was deported twice, once in 1997 and again in 2001.

Some critics of the ad have noted that the last time he entered the country illegally appears to have been during the presidency of George W. Bush. He didn’t let Bracamontes in either, though. The fact is that Bracamontes evaded law enforcement, which is not in itself noteworthy. The rate of success for people who attempt to enter the country illegally multiple times never dipped below 96 percent until 2008, according to the Mexico Migration Project, the most comprehensive sociological database to track migration across the U.S.-Mexico border.

Implying that the migrant caravan is consists of dangerous criminals like Bracamontes is just as untenable as the claim that Democrats let him in. Among the several thousand people traveling through Mexico in the main caravan are 2,300 kids, according to UNICEF USA. The migrants are banding together in caravans not as some kind of invading force but as a way to seek protection in numbers from human traffickers.

The major challenge that the U.S. faces at the border is how to process efficiently an uptick in the number of Central American families and children who make asylum claims or ask for other forms of humanitarian relief from deportation. But that trend dates from 2014, so it’s hardly new.

It won’t be clear until after the midterm elections whether Trump will follow through on his barrage of immigration promises. But with less than 24 hours to Election Day, the more immediate question is how voters will react to his statements.

Mass migration from Mexico had petered out seven years before Trump launched his campaign for the presidency by vilifying Mexican immigrants as criminals and rapists and blaming “open border” Democrats for an immigration crisis that didn’t exist. The strategy helped get him elected in 2016. On Tuesday, we’ll see if it works for him again.