They often actually make a hahaha sound, as if they’re expelling something caught in their esopahagus.
They will glance around, in a jolly manner, indicating to their fellow audience members, “That was a good one!”
If they disagree with a punchline, or its political content, they get very stern and will tell their spouse, “Not funny.”
If they’re drunk, they’ll laugh at anything, and even merrily slap their thighs. This can be endearing or annoying.
The most uptight right-wingers won’t laugh at all, but instead will announce, “That’s funny”, as if they’re the presiding Judge at Komedy Kourt.
When liberal people laugh:
Nervous white liberals will often check in with other audience members, to see if it’s permissible to laugh at something which might be offensive. They will glance beseechingly at any minority member, for guidance.
They will laugh especially loudly at anything which ridicules Republicans, while vigorously nodding their heads in agreement, as if they’re voting.
Liberal women will sometimes cover their mouths when they laugh, geisha-style, if they’re laughing at something naughty. In a similar situation, a conservative woman won’t laugh at all, but she will stare at whoever’s laughing, to shame them.
If they’re drunk, liberal males will laugh uproariously and high-five or fist-bump each other. This can be endearing or sad.
When white liberals laugh at African-American comedians, they feel better about America.