I would say there are just as many saying the revenue side shouldn't be touched.
Both sides need to be on the table.
The problem is that there's only so much additional revenue we can realistically expect to raise....at least in any sustainable fashion.
Revenue generation has long just bounced between a range of ~14% - ~18%....and usually tracks with economic performance. Revenues naturally go down during weaker periods of growth and naturally go up during stronger.
Trying to squeeze the goose's body too hard will only result in impairing his ability to lay the golden eggs. And it's the golden eggs we need. Maximizing growth should always be a primary focus. And I don't mean the kind that comes briefly from Keynesian infusions of demand. The more our economy is growing, the less pressure it will require to repair our fiscal footing.
Spending is far more within policymakers' control than either growth or tax revenues. But (a) the biggest source of fiscal pain is the non-discretionary funds that nobody wants to touch, and (b) even talking about the discretionary funds makes many people shriek in absolute terror.