You have outlined the problem, however what you missed is that in the sixties and seventies folks were convinced that two children were enough. That would give us only one worker to pay into SS for each worker. It's a ponzi schism after all.
Yes, that is how we got into the demographic hole in the first place.
White, Middle Class America has committed demographic and political suicide and now we are facing the consequences of our demographic suicidal actions.
The only realistic way to deal with the problem is to increase the population to grow our way out of our economic and demographic disaster we have created for our selves.
The best way to increase the population is to import young, productive highly skilled and highly educated people from countries with a similar culture and values to maximize economic growth and facilitate assimilation.
To quote the most famous of Tonto's quotes, "What do you mean 'we,' white man?