Lindsay Lohan -- Back in the Danger Zone

Lindsay Lohan reentered the NYC party scene last night -- where she was arrested last month -- raging until 3AM ... and TMZ has the footage.

Lohan must've been pining for some raw fish -- 'cause she rolled into Catch in the West Village -- a fancy, bumpin' sushi joint that's been described as "lively and loud."

Lohan didn't leave the place until 3:15 AM -- beelining straight for a waiting SUV that whisked her away. The move might've been a message to Michael Lohan -- who's leading efforts to get Lindsay into rehab.

But it wasn't all tuna rolls and club music for Lohan last night -- she actually watched the debate ... and even tweeted support for Barack Obama during the event ... writing:

"RT @BarackObama: RT if you're #ProudOfObama as our commander in chief."

Funny, considering she JUST announced her support for Mitt Romney two weeks ago.