I have to agree with Tom on this... While it would not be determinative on my decision to carry a back-up gun, it has to be a factor you consider.
An average juror doesn't understand the reason for carrying a gun at all. He or she has never been attacked, and/or has victim mentality -- wouldn't want to use a gun if they could. The mere fact that you carry a gun at all makes you look like a bit of a vigilante...
If you are carrying TWO guns (again -- they would never consider carrying ONE), you look like someone who really expects to have need for a gun -- like you are looking for trouble and hoping to use your gun.
CAVEAT: You all know me well enough to know I am not endorsing this ridiculous point-of-view -- I just recognize how people see things.
Chris -- the juror's won't see your spare tire analogy. To them, the back-up gun is like carrying a SECOND spare tire. Its yet another heavy, cumbersome thing taking up space that you should likely never need. Why carry a second spare unless you are pretty darn sure you are going to get a few flats. Right?
Of course, stay out of trouble and you may never face a jury. However, I think cops will see it the same way for people who are not cops. Just like the predisposition that good guys use holsters and bad guys don't -- two guns will strike them as someone looking for trouble. Cops have a lot of discretion and you don't want to be on the wrong side--they can sink you pretty quick.
My two cents worth.
