One good government program deserves another?

One of the arguments I keep hearing from liberals is that social security and medicare are government programs and most people like them.  So therefore we should have government run healthcare.  I have not heard anyone counter this.

The problem I have understanding this is I believe they are leaving something out.  We have been making explicit payments to both of these programs since their inception.  They are more like insurance since we have been paying all along.  (I know they are broke since we have been mismanaging them)  But, none the less, they are self funded programs (in theory)

But, it seems disingenuous to compare these programs to the government run health care proposal.  There will not be equal contribution from all to support this.   It is a flat out giveaway.

Why do conservatives allow the left to shout us down on this?