You can't. He's trying to use liberal as an epithet when he means neoliberal. If we're being pedantic, liberal refers to the full gamut of people who think there should be an open and free society, which usually includes a market and certain property rights. The conservatives use liberal as an epithet to decry the left and now the left is using it to decry the middle.
It would be funny if it wasn't being used to convince naive progressives to sit out elections and let fascists seize power because the center left "only" wants 85% of what they want. You're seeing it really ramp up because the US is closing in on a big election, and convincing dipshits to sit out elections is easier than convincing anyone the right can govern.
