The congressmembers were slated to appear for an "America First" fundraising rally this weekend in Orange County -- just the latest stop in a series of similar events they've been hosting since the spring -- initially booking something at a venue in Laguna Hills.

Once word of their event started to make the rounds online ... tons of people vowed to try and get them canceled by blowing up the venue with calls, and even protesting in person if it came to it. Before that could even occur, though, the place gave Gaetz and MTG the boot ... canceling their rally amid public outcry, both in and around the SoCal beachside city.

After that, they were on to Plan B ... changing venues to the Riverside Convention Center. However, that too became public -- and the exact same thing happened again, including Riverside honchos telling them to scram. Their final attempt would be ... Anaheim.

They secured space at the Anaheim Event Center -- but after city officials publicly disavowed their appearance (plus the fact this venue had decided to host them) the Event Center people finally pulled the plug in the 11th hour. Seems like some power lobbying was at play.

Now, it appears they'll be hosting their rally -- which is being called a protest at this point -- back in Riverside ... but they'll be doing it in the streets outside of City Hall.

If anything, that'll probably end up being even more contentious than whatever they planned to hold indoors ... we're sure counter-protesters will show up (as they always do) and confront the far right-wing politicians and their supporters face-to-face ... which could get ugly. We'll be monitoring the scene as it plays out -- but something tells us cops aren't looking forward to the storm that's coming. Ditto for local residents, who might wanna steer clear.

Like said, this was reportedly supposed to be to raise money at first ... but at the moment, it looks like Gaetz/Greene are just gonna be out there railing against "communism," "cancel culture," "the far left" and "the stolen 2020 election" ... buzzwords they've been using lately.

It's pretty fascinating -- these two are definitely Trump disciples, and parrot what he says too ... but Trump-centered events have been allowed to go down in the OC without issue before.