I may buy a gun for when I volunteer at our local Democratic office. Seeking advice.

[sarisataka]

19. First question is who is in charge of the office?

It may be legal for you to carry however you may lose your position if you violate the code of conduct, or whatever the office guidelines are called.

Second issue, you talk about discouraging volunteers; why do they need to know? I have friends who have known me for years and they would be surprised, not that I carry, but that I am carrying in their presence. I do not advertise and on the rare occasion the subject of carrying comes up I will admit to having a permit. After that, concealed means concealed.

Your description of the office places you at the rear of the office with most people between you and the door, the likely position of an attacker. That places a lot of innocent people in your line of fire, not a situation even a well-trained, experienced shooter would envy.
40 ft. is a significant distance for firing a handgun under stress, also not a situation favoring a novice.

You indicated you would keep the gun in a drawer- that is a serious issue. Either the drawer is unlocked, which means you have an unsecured firearm in a busy office. It could be found by anyone looking for the stapler. If the drawer is locked, it is an access issue in case of emergency and given the quality of desk drawer locks, it is "secure" in only the most cursory way. Murphy's law also would indicate that if you actually needed the gun, you would not be at your desk but elsewhere in the office, making the paperweight at hand far more useful. The only way to carry securely is on your person, preferably using a retention holster.

My advice is to look to other avenues than buying a firearm.