Fox News commentator Tomi Lahren is telling Michelle Obama to "sit down" after taking issue with the former first lady calling her husband Barack Obama a great president.

"Michelle Obama said we 'had' a great president. By what measure? Not in economic growth. Not in border enforcement. Not in strength on the world stage. Sit down, Michelle," Lahren wrote to her 1.18 million followers in a tweet.

Lahren, who will be hosting a show on Fox's soon-to-launch subscription service called "Fox Nation," was responding to remarks Michelle Obama made at a rally in Las Vegas.

"Here's what we have to do," she said at the "When We All Vote" rally. "If we want qualified people that we trust, then people have to vote. Because you can't vote some of the time and then sit out."

"You know, we saw that happen. We experienced that. But we had a great president," she said, referring to former President Obama.

"But every couple years folks sat out and said 'well, I did my part, I voted once, I'm done, I'm out,' " she added. "And I'm just telling you that democracy doesn't work that way."

Michele Obama is a co-chairwoman of When We All Vote, a nonprofit initiative to register voters.