heck i looked into this during the bush administration. it seems pretty hard unless you have work outside the country to get you out, or lots of cash. also, you'll still be an american citizen and it's often difficult to become a naturalized citizen. iirc when i was looking into it i was looking to canada and you have to have been a resident for a decade.

anyway this is one of the reasons leftists often say borders are bs

things might change if it ever comes to a point where countries offer asylum, but that i assume that wouldn't happen unless the us government is engaging in clear and open systematic persecution of minority groups