On Wednesday, CNN analyst Juliette Kayyem joined Boston Public Radio to explain the ramifications of President Trump’s latest promise to bar legal immigration to the U.S. for 60 days.

Kayyem called the president’s forthcoming executive order to temporarily suspend green card certifications “silliness,” and said the measure would do little more than woo his base of anti-immigrant supporters.

"Why did he do this? ‘Cause he got the tweet to help his base in terms of saying [he’s] stopped immigration. It has no impact, literally no impact,” she said.

On Monday night, the president tweeted that he would “temporarily suspend immigration into the United States,” leaving many to ask when or how. On Tuesday, he revealed plans for an executive order that would temporarily suspend green cards approval, without impacting workers coming to the U.S. on a temporary basis.

Read More: Trump Vows To 'Suspend Immigration,' Adviser Cites Health

"Getting a green card is a multi-year process– 60 days is nothing,” Kayyem said.

The “Security Mom” author added that she was doubtful the president will impose stricter immigration restrictions, for fear it would damage an already struggling U.S. economy.

"The most important thing I think on this is what he didn’t do,” she said. "It is clear to me, and he’s right in this sense, that any… limitations or curtailments on immigration right now will have such a tremendous economic impact, in a bad way, that he won’t touch it.

"We would not be able to open back up with harsher immigration policies, and he knows that,” she said.

Kayyem is an analyst for CNN, former assistant secretary at the Department of Homeland Security and faculty chair of the homeland security program at Harvard University’s Kennedy School of Government.