Political Signs in the Common Area

We have a very small HOA (eight townhomes on a corner lot in the L.A. area). At our board meeting the other night one of the owners asked if he could put up a campaign sign. This has been an issue in the past, but was never seriously addressed, so I agreed to do some research. Our CC&R has the typical verbiage disallowing all signs except For Sale or Rent, but I also read about 1st Amendment issues overriding CC&Rs, and states passing laws expressly exempting political signs from these rules. (I couldn't find a specific law for California, so if someone knows of one and can point me to it, I would appreciate it.) But here is the problem I am having. Most of what I have read seems to refer to signs on private property (i.e. lawns in HOA controlled communities). Although four of our units face the street, and have a narrow strip of lawn between the unit and sidewalk, everything not specifically in an individual unit is considered the common area. So even though the person would be putting the sign on what looks like "their" front lawn, it is really common ground. Does this carry any weight in terms of 1st Amendment rights (or lack thereof)? We have already agreed they are free to put any signs they like in their window, and it's not like anyone is ready to go to war over the issue, but I am curious if the fact it is considered common area makes a difference, one way or the other.

The HOA can prohibit the signs on common areas but not on the individual units but they can limit their size even there.

Civil Code §1353.6. Right to Display Signs, Posters, Flags and Banners.

(a) The governing documents, including the operating rules, may not prohibit posting or displaying of noncommercial signs, posters, flags, or banners on or in an owner's separate interest, except as required for the protection of public health or safety or if the posting or display would violate a local, state, or federal law.

(b) For purposes of this section, a noncommercial sign, poster, flag, or banner may be made of paper, cardboard, cloth, plastic, or fabric, and may be posted or displayed from the yard, window, door, balcony, or outside wall of the separate interest, but may not be made of lights, roofing, siding, paving materials, flora, or balloons, or any other similar building, landscaping, or decorative component, or include the painting of architectural surfaces.

(c) An association may prohibit noncommercial signs and posters that are more than 9 square feet in size and noncommercial flags or banners that are more than 15 square feet in size.