How can Congress in good conscience exclude themselves from Social Security yet continue to deplete the fund.?

As I understand the program, we the people continue to lose our benefits and watch benefits diminish, while elected government officials continue to increase benefits for their own medical and retirement benefits at our expense and refuse to participate in a program that they have no vested interest in. Seems to me that the problems surrounding Social Security would be solved by having all citizens, sovereign and foreign, privileged or not, be under the same rule and system. This would not only reduce government spending but restore the viability to the Social Security system and have all participants on the same playing field. If I am not mistaken, the social security system at inception was to supplement retirement for all participants and all wage earners were to participate in the program...no exclusions. It was also to benefit participants as they became eligible for retirement and not to be earmarked as largess for the population at large.