Gun wielding protestors serve as a distraction and an additional drain upon already strained Secret Service resources. Once someone shows up with an AR-15 or a pistol on his thigh, at least one law enforcement officer is dedicated solely towards keeping an eye on that person. With as many as a dozen individuals openly carrying weapons, even while it's completely legal, it draws the attention of security personnel to manage those weapon carrying individuals.
It may be perfectly legal for individuals in said state/city to openly wear firearms. They may be responsible citizens with no intention of inflicting harm on anyone. But their presence servers as a distraction. They bring guns that they may not be able to control in a scuffle with an aggressor. And should an incident occur, not being trained protection officers working in coordination with Secret Service, the gun holders risk harming crowd members and Secret Service members responding too an incident and neutralizing a threat.
If I were to "legally" bicycle up to the Presidential motorcade, wearing only a pair of swim trunks, I would without a doubt be pulled aside (tackled more likely) and prevented from bicycling alongside the motorcade. I would be breaking no laws, but would still pose a security risk, even if I had absolutely no weapons. (Similar scenario)
But in the case of these gun-toting protesters, (any supporters?) this administration is overly mindful of the 2nd Ammendement, and the need to be perceived as not having a bias against guns. And we somehow allow this increased threat to exist and strain resources dedicated to keeping the President and the crowd safe.
So with all of that attention diverted to keeping an eye on the open carry guys. How many eyes are no longer scanning the crowd for the one individual without a weapon showing, with a far away look in his eyes? These distractions increase the risk to the President and those Secret Service agents who are willing to take a bullet for him. (someday, her)
Members of Congress and their staff, I'm glad that you've read this far. Upon return from August recess, please take up an emergency measure to increase the budget for the Secret Service to respond to the growing threat level aimed at this Administration. You don't have to mix "Gun Control" into this measure. Let the Secret Service set the rules for what is and is not permissible in a Presidential setting, but give them the resources to do their job safely.
I know you are concerned for the President's safety and the safety and civil rights of people attending these events. Please do the right thing and increase assets for the Secret Service.