Well, that sniper definitely is a dumbass,
Your typical presidential motorcade:
See those Cadillacs? They aren't anything like a Cadillac from GM. It weighs in at 20,000 pounds. They're built on Medium Duty Truck frames, Dump trucks use those frames. They make armored trucks look like toys.
The doors are 8 inches thick, the windows are 6 inches thick, a bullet from a sniper will literally scratch this. Not only is there 1 of these in a motorcade, but there's 2–3. You won't be able to know which one the President is in until your literally right across from it. Anyways, if you were still stupid enough to take a shot at the president’s limo, here's all the defenses.
Typical SUVs, right? Nope. One has a Dillon M134 Gatling Gun in it, and the other is a frequency jamming device, (antennas). You won't be able to figure out if the Gun is actually in it, unless of course they need to use the Gatling gun. Not only that, but in total, you're looking at 30–40 Secret Service Agents in the vehicles. Not including Secret Service Snipers, Police lined up along the route, and people monitoring all calls in the area of said Motorcade.