100%. This is why they want such a huge crowd in DC close to the White House and it is also why the mayor will try to shoo away the National Guard and police. Considering the huge push for an above average turnout at the riot happening at the end of the week and the withdrawal of as much law enforcement they can get away with, the rioters will outnumber remaining law enforcement by an even bigger ratio. This is going to embolden the rioters big time and they will push the front line closer to Trump. Faced with the reality that no reinforcements are coming to help them, the Secret Service will be forced to make a decision: use live rounds or abandon the White House.
If they fire on the rioters, the narrative will change to, "See!! Trump was a mass murdering Hitler jr. all along! He gave the order to mow down peaceful protesters over an arbitrary, invisible line in the lawn!". Then the dog piling will start. Almost all high profile politicians, including Republican ones, will condemn him and call for his removal. He will be sued, indicted, impeached again, no expense will be spared and no tactic unused to remove him. They will make sure he's out and the PR/threat of cancellation from the cult will make sure the GOP is finished being a serious political party on a national scale.
If they flee the White House, it will make Trump look extremely weak. The White House will be burned, the priceless artifacts it contains will be looted and destroyed. He will lose the support of a large chunk of his voting base if not the majority of it. Conservatives will become so demoralized that it will greatly weaken any resistance being put up by Conservative America in the political sphere.