The simple answer is stated by Jason Easley in the first sentence of his post, Republicans Kill The Hostage As S&P Downgrades US Debt
S&P downgraded America’s debt because the Republicans have made the process of governing so dysfunctional that Washington can no longer be trusted to agree to make even the most basic decisions.
In fact, that is exactly what Standard & Poor’s says in the Rationale section of it’s written explanation for the downgrade. Here is an excerpt:
We lowered our long-term rating on the U.S. because we believe that the prolonged controversy over raising the statutory debt ceiling and the related fiscal policy debate indicate that further near-term progress containing the growth in public spending, especially on entitlements, or on reaching an agreement on raising revenues is less likely than we previously assumed and will remain a contentious and fitful process. We also believe that the fiscal consolidation plan that Congress and the Administration agreed to this week falls short of the amount that we believe is necessary to stabilize the general government debt burden by the middle of the decade.
Our lowering of the rating was prompted by our view on the rising public debt burden and our perception of greater policymaking uncertainty, consistent with our criteria (see “Sovereign Government Rating Methodology and Assumptions ,” June 30, 2011, especially Paragraphs 36-41). Nevertheless, we view the U.S. federal government’s other economic, external, and monetary credit attributes, which form the basis for the sovereign rating, as broadly unchanged.
We have taken the ratings off CreditWatch because the Aug. 2 passage of the Budget Control Act Amendment of 2011 has removed any perceived immediate threat of payment default posed by delays to raising the government’s debt ceiling. In addition, we believe that the act provides sufficient clarity to allow us to evaluate the likely course of U.S. fiscal policy for the next few years.
The political brinksmanship of recent months highlights what we see as America’s governance and policymaking becoming less stable, less effective, and less predictable than what we previously believed. The statutory debt ceiling and the threat of default have become political bargaining chips in the debate over fiscal policy. Despite this year’s wide-ranging debate, in our view, the differences between political parties have proven to be extraordinarily difficult to bridge, and, as we see it, the resulting agreement fell well short of the comprehensive fiscal consolidation program that some proponents had envisaged until quite recently. Republicans and Democrats have only been able to agree to relatively modest savings on discretionary spending while delegating to the Select Committee decisions on more comprehensive measures. It appears that for now, new revenues have dropped down on the menu of policy options. In addition, the plan envisions only minor policy changes on Medicare and little change in other entitlements, the containment of which we and most other independent observers regard as key to long-term fiscal sustainability.
Our opinion is that elected officials remain wary of tackling the structural issues required to effectively address the rising U.S. public debt burden in a manner consistent with a ‘AAA’ rating and with ‘AAA’ rated sovereign peers (see Sovereign Government Rating Methodology and Assumptions,” June 30, 2011, especially Paragraphs 36-41). In our view, the difficulty in framing a consensus on fiscal policy weakens the government’s ability to manage public finances and diverts attention from the debate over how to achieve more balanced and dynamic economic growth in an era of fiscal stringency and private-sector deleveraging (ibid). A new political consensus might (or might not) emerge after the 2012 elections, but we believe that by then, the government debt burden will likely be higher, the needed medium-term fiscal adjustment potentially greater, and the inflection point on the U.S. population’s demographics and other age-related spending drivers closer at hand (see “Global Aging 2011: In The U.S., Going Gray Will Likely Cost Even more Green, Now,” June 21, 2011).