One is the influence of the Koch family in wanting to dismantle social programs. Much of the argument about the debt was put forth by the Kochs with their funding of Cato and Heritage. Pete Peterson added to the argument with his installation of the debt clock.
Refer also to the "Two Santa Claus Theory." You can google it. T.S.C.T. is what this is really about.
Much of this is bullshit. But if you want to believe it is a problem, ask why Republicans didn't complain about it during the Bush administration with their tax cuts and unfunded wars. Why now?
If it really is a problem, why the resistance to increasing revenue?