A guest on FOX Business suggested Vice President Kamala Harris slept her way to the top live on the air -- and he did so by invoking none other than the now-viral Haliey Welch.

Author Alec Lace went on the network earlier this month to talk shop, and it quickly became clear he was no fan of Dems or the VP, especially when he referenced her in very vulgar terms.

The shocking moment is just now going viral because of Harris' presidential campaign.

Watch ... Lace was trashing Kamala, calling her the "DEI Vice President" and saying the Democratic party's prospects are grim. Then, he called KH the "original Hawk Tuah girl."

You can see some of the other FOX hosts sitting next to him react to the wild description -- with Dagen McDowell being the only one to react with words ... calling his cheap shot "harsh" and "tough." The other two hosts also seem to agree ... but no other pushback from them.

Again, it seems like his remarks flew under the radar when they first went out over the airwaves over 4th of July weekend ... and the reason it's getting picked up and circulated now is because Lace himself retweeted the clip amid news Joe was out and Kamala was in.

Despite the obvious misogyny in his unsubstantiated smear, AL stands by it -- telling TMZ, "Kamala Harris and the Biden administration are destroying our country. The last thing I’m worried about is saying the quiet part out loud about how Kamala got where she is today."

He adds, "I’m more concerned with how the MSM has radicalized people with their dangerous rhetoric about President Donald Trump which almost got him killed."