There is no 'slippery slope' toward loss of liberty, only a long staircase where each step down must first be tolerated by the American people and their leaders.
The welfare state is predicate don collecting money from today's workers in order to pay for those who paid in before them. But today's workers don't have enough money to sustain the scheme, and there are too few of them to do so. As a result, virtually every welfare state in Europe, and many American states, like California are going broke.