How do people really expect this to work? In detail? You show up with an armed militia at a school and the ICE guys just drive on past (and then raid someone else)? Or are they expecting more of an Amerimaidan situation? Jan 6th situation?
Coordinating with your neighbors and compatriots is essential from the soap box, to the ballot box, to the jury box, and to the cartridge box. And I'd like to emphasize the order of those boxes should be followed.
Like pjc50, I'm British by birth, though I no longer live there. Like most Brits, the USA's 2nd Amendment isn't something we look up to, it's something we consider deeply weird. Even UK police are not routinely armed, and I've seen polls saying they don't want that to change.
And also like several commenters here, I don't think it's going to make much of a difference. Trump was actually fired at, albeit by an idiot, he still supports the 2nd Amendment. Either the armed forces step in on the side of the constitution, or they step in on the side of the administration, but either way the 2nd Amendment isn't going to make a difference: the guerrilla teams use AR-15s, the military can afford to respond with drone strikes.
ICE is thuggishly and sloppily prowling places like Minneapolis because statistically they can get away with it without causing too many bodies. Up the potential body number and their tactics are forced to change for the better.
If the statistical average door they kick in in Minneapolis had the same likelihood of "shit I ain't going back to prison <bang> <bang> <bang> <dives out bathroom window and hops neighbors fence>" behind it as the statistical average door in St. Louis ICE wouldn't be behaving the way they are in MN. They would have specific targets, specific places and times to pick them up, etc, etc. (i.e. operating like the local professional police do) because the risk calculation with even a tiny change you might get shot back at, even if only ineffectively, makes that (much higher) resource expenditure pencil out, with consequences in terms of how much they can get done.
Personal ability to credibly threaten lethal violence if cornered (note: I did not say "firearms") acts much like an ATGM or MANPADS for an infantry squad. You're not gonna take a squad with TOWs on the offensive against a bunch of tanks, but if attacked you've at least got a prayer. The same math holds on the individual level. Making any potential target substantially more prickly to a potentially superior force and doing so for little cost is a huge boon for the little guy. A firearm is a force multiplier same as a bomb carrying drone or a cell phone that records things the government does not like or a media platform that puts those things in front of the eyes of the masses. It forces the superior force to still be much more careful and expend far more resources when engaging. When it comes to domestic policing what this means is that ICE would be under more pressure to "be careful and professional" in every city like the DEA did during the war on drugs we wouldn't even be having this discussion because they wouldn't be employing the tactics that everyone hates.
This math is a large part of why drugs won the war on drugs. There were enough glawk fawtys wit da switch kicking around on the "wrong" side of the law that the cops needed to adopt militarized tactics, the public didn't wanna pay for that shit (monetarily or politically) over weed, and thus drugs won the war on drugs. If they could've rolled up on just about anyone "cheaply" with just a few cheaply (poorly) trained cops, minimal equipment and support, minimal planning and surveillance, etc. it would've gone on way longer (but they couldn't, because that would have yielded too many bodies and cost too much political capital).
You know where are all NRA and "have gun against govermental tyrrany" guys? In the ICE or supporting from sidelines. And they are itching for when they will finally be able to commit even more violence.
I'm convinced the whole point of pulling a phone out to film a murder is because they having a long-term strategy for slowly boiling the frog and it's gamified for agents. I'm certain that dude got a bonus, an award, and is up for promotion for walking the administration up the next rung of the tyranny ladder.
"achievement unlocked"