The US is transitioning from being a dominant superpower to being one in a herd. Saying that the current approach is works is also difficult position to sustain. They probably should try something different.

The basic position is that a government should raise enough taxes to cover its expenses. You can call that ideological and suggest there are superior options if you want to. Maybe there are, a little debt can be a good thing. But to suggest it won't work is a bit out there. It works. It is one of those simple strategies that is too boring to fail.

Also, if the strategy switches from spending more than you earn to less, obviously there will be a period where people are worse off. It is the same with paying back any obligation. Overspending foolishly obviously increases living standards while it is happening - the problem is the part where people no longer fund the debtor and said debtor didn't invest in productive capital. You need an argument that accounts for that to claim austerity fails. It is expected to do worse than the status quo for a while. Saving money isn't much fun on Day 1 either, it can take a decade to pay off.