Likely not successfully.
Generally speaking, (laws vary), on private property, citizens have fewer rights, but they still must exhibit violent intent before you can use lethal force.
They must enter the residence without permission, ideally breaking a lock, door or window, or employ a deadly weapon against the residence from outside. Either establishes intent and fear for life.
A group that agrees to, travels to, and trespasses upon private residential property establishes a conspiracy and each is responsible for the criminal acts of the other. This does not apply to public property.
Persons acting peaceably outside, and not attempting to enter a private residence are trespassing and can be arrested and prosecuted for that, but must put the resident in fear of his life to be legally shot.
A noisy, angry mob of Marxists crowding around your door? First of all, they've imprisoned you in your own home--and that's a forcible crime of false imprisonment right there. Are going to wait until they actually look ready to torch the house?
Say hello to my little friend, SEIU goons.
Yep, makes sense... if a group of folks showed up at my door, banging and clamoring, I cannot wait to see if they mean me bodily harm, I get my gun, call the police, and stand ready to shoot... if I think they may be trying to enter, I shoot, bastard is dead, I defend my action... tell me a jury is going to convict me of homicide.