Tbf "liberal" in American political parlance implies socially liberal. I.e you don't actively want to kill all gay and colored people just for existing. That's why republicans, despite being liberals, don't want to be called liberals.
It starts making even less sense, however, when they call liberals commies, because those liberals are mostly actually liberals in the classic sense of the word too.
Funnily even here in Estonia, simply being pro LGBT rights gets you labeled a marxist or communist by the ultraconservative party. Even if you're not actually advocating for any communism adjacent economic policies. Hell, they'll call the liberal party communists... While the liberal party wants to cut taxes and government spending, and the ultraconservatives/nazis are against cutting government spending (because they're only conservative in that they're incredibly xenophobic, not in terms of economic policies).
Words have simply lost all meaning in modern mainstream political discourse. Yay.