Mayors who belong to "Mayors Against Illegal Guns," represent virtually none of the mayors in the US

Given that there are over 35,000 cities and towns in the US, having 950 belonging to MAIG seems pretty small.  That comes to about 2.7 percent.  The cities that they have lost include: Rockford, Ill at 150,843, Nashua, N.H. at 86,933, and Sioux City 82,719.

Many of the members of MAIG come from small population towns.  I haven't checked through, but my impression is that the new members are also from relatively small places.

There are seven mayors from Arizona.
Paradise Valley: 13,035
Tolleson: 6,655

There are four mayors from Arkansas
Forest City: 15,237
Helena: 12,106
Hughes: 1,422
Wrightsville: 2,114

Lots from California (I am not going to take the time to go through all the cities, but here are a few and not necessarily the smallest ones.)
Benicia, CA: 27,426
Blue Lake, CA: 1,253
Brisbane, CA: 4,282

Campbell, CA: 40,272 Claremont, CA: 35,457 Corte Madera, CA: 9,377 Emeryville, CA: 10,335 Fairfax, CA: 7,534 Gonzales, CA: 8,364 Gustine, CA: 5,625

Healdsburg, CA: 11,440
Malibu, CA: 12,832
Morgan Hill, CA: 39,420
Orange Cove, CA: 9,580
Patterson, CA: 20,659
Ridgecrest, CA: 28,325
San Anselmo, CA: 12,491
San Luis Obispo, CA: 45,878
Signal Hill, CA: 11,185
Tiburon, CA: 9,093
West Hollywood, CA: 34,781

There are thirteen mayors from Colorado
Boulder: 101,808
Englewood: 31,177
Golden: 18,867
Lafayette: 24,453
Lakewood: 145,516
Louisville: 19,074
Manitou Springs: 5,172
Nederland: 1,445
Northglenn: 36,891
Salida: 5,317
Superior: 12,782
Telluride: 2,325

There are four mayors in Delaware:
Blades, DE: 1,241
Dewey Beach, DE: 341
Middletown, DE: 19,483
Wilmington, DE: 71,292