(This is cross-posted from ProgressiveFix.com, the new online face of the Progressive Policy Institute, where I will be posting regularly.  Give 'em a look.)

In my last post, I noted that progressives need to turn their attention toward the medium- and long-term fiscal crisis the country faces. How massive is the challenge we face? The following chart, from Keith Hennessey, an ex-Bush policy advisor, says it all:

Obviously the first thing to jump out is the escalating divergence between federal spending and revenues in the decades ahead. And the spending projection in the chart is from 2007, so it doesn’t include the stimulus or spending on the financial crisis (or the projected cost of health care reform). That’s scary enough. But the scariest part may not be evident at first glance.

The red line shows federal taxes as a percent of GDP going back to 1945 and projected outward to 2080 by Hennessey based on its historic growth. The yellow line shows federal spending as a percent of GDP. The chart makes clear that the level of federal taxation has actually varied little since World War II (which says nothing about how marginal tax rates faced by different groups have changed). You can see the last build-up of deficits that occurred from the 1970s through the mid-1990s. You can also see the build-up of the Bush years.

Historic Shortfalls The kind of budget shortfalls we are looking at in the future dwarfs anything we’ve ever seen. There are two ways to close the fiscal gap – cut spending or increase revenues. What Hennessey’s chart makes clear is that the level of taxation it would require to meet projected spending needs is far higher than anything the country has ever seen-slash-tolerated. Indeed, even closing half the gap through higher taxes would necessitate historically unprecedented taxation levels.

Progressives, in short, are going to be caught between a rock and a hard place: we will either have to find a way to convince the electorate to go along with massive tax hikes, with all of the electoral risk that entails, or we will have to come up with a plan to make equally massive cuts to entitlements that are likely to also be unpopular and that may do significant harm if not thought through carefully.

It’s true that the right will also be caught in this dilemma, but its situation is not quite as severe for two reasons. First, as the chart implies, their preferred path to fiscal sanity (spending cuts) starts off a much easier sell than tax hikes, given historical patterns. And second, the right has little programmatic interest in permanent spending hikes. The Reagan and Bush years showed that there is a constituency on the right for greater defense spending, but unless we really end up permanently at war with radical Islam, it can be expected that the Pentagon’s budget will rise and fall as global circumstances dictate. Progressive goals, on the other hand, such as greater federal education spending, expansion of child care assistance, more generous safety nets, and broader social insurance constitute costly and (ideally) permanent spending increases that will exacerbate the fiscal gap in the above chart.

The Upshot for Progressives What does this mean for the progressive agenda? First, it is vital that we prioritize our goals, a process that is going to require us to drop many of them, as difficult as that may be. Second, we need to come to terms with what “higher taxes” is going to mean in practice. U.S. taxation is actually as progressive as in Europe because we have taken so many families off of the income tax rolls. The added boost to raising taxes on “the rich” is much smaller than the revenue that could be raised by broadening the tax base so that we were not so reliant on upper-income families to pay for the benefits of government that everyone enjoys.

Third, we need to look for ways to achieve progressive aims that do not cost the federal government so much. That could include certain types of regulation, but it could also include a shift toward progressive cost-sharing in social insurance programs. Rather than trying to raise taxes to give people the benefits they say they want, we could move toward a paradigm where people gradually incur increasing costs of these benefits privately, forcing them to directly confront the trade-offs and efficiency concerns that social insurance tends to hide. Those with limited incomes could receive federal assistance but would still be incentivized to use benefits efficiently. (I will suggest what such programs might look like in future pieces here.)

Some progressives may object to the idea of progressive cost-sharing because it shifts costs and risk onto individuals. But they are going to incur the costs one way or another, whether through higher taxes or greater out-of-pocket spending. And given the impracticality of paying for future benefits solely out of taxes, risk is also likely to be privatized either way — whether by a thoughtful policy framework or through massive cuts in existing programs.

But let there be no doubt — the long-term prospects for significantly expanded progressive government are dim, and in fact, a retrenchment in coming decades is inevitable. President Clinton was wrong — the Era of Big Government is not over. But it will be soon. As progressives we must lead the process of winding it down in a responsible and fair way.