You simply aren't going to be able to provide a lower class a comfortable life by giving them work that doesn't actually need doing. Worse, trying probably ends very badly.
But that's the problem right there: It will not work, and in fact it will make things (possibly much) worse.
As for "until the system changes": How do you think the system changes if you try to band aid it? Who is then fighting to change it?
Systems change not generally in smooth realization that things are not going to go well 50 years from now, but instead when things hit the breaking point and the lower class revolts.
See,e.g., the history of the world elsewhere.
Sad, but true.
This may the the only real hope. But what about these people until then?
Rather than doling out welfare, it looks like Trump is shifting wealth around by increasing the incentive to hire Americans at the cost of more expensive goods and slightly smaller margins.
It's unorthodox, but is it foolish?