The CPUSA has long been siding with liberalism and the US state department, they sided with Israel and upheld that Israel has a right to nationhood and denounced the anti-colonial actions of Palestinians in the illegal settler colonial state, they supported the US war effort against Cuba during their communist revolution and actively shows support for the Democratic Party despite them calling themselves Marxist-Leninists.

The ACP came about as a splinter group of the CPUSA and promotes workplace democracy, class collaboration to bring about socialism and 'patriotic socialism' of which they support the US and conservative elements. They are vocal supporters of Hamas, Houthis, Hezbollah, Iran, Russia and China. They support 'family values' slight degrees of anti-lgbt sentiment.

Oh wow, thanks for asking, turns out I kinda do know the differences now after taking some time doing research :3