Clear Thinking About "The Gap"

In a post today on Space Politics, Jeff Foust displays some rather clear thinking about the so-called manned-spaceflight gap:

One thing to remember with all this discussion of a gap, including claims that it is “a national security issue”, is that it refers only to the US Government’s ability to send humans into space on vehicles it operates. Should one or both of the COTS awardees, or another company interested in commercial orbital spaceflight, be successful, the gap would be greatly reduced—or even in the best case eliminated—simply by having the government procure transportation services.

Of course, this raises a question about another oft-repeated line of thought about why Congress wouldn't dare cut funding for implementing ESAS: that no Congress member would ever vote to end US manned spaceflight. I've raised this point before, but it bears raising again. If 2010 rolls around, and Ares-1 hasn't even flown in its full configuration to orbit, but one of the commercial companies has started flying people and crew to orbit, how seriously should Congress take this claim? Why shouldn't Congress at that point outright cancel Ares-1/Orion and force NASA to purchase flights to LEO from commercially available domestic sources. If commercial manned spaceflight becomes a reality in that timeframe, it becomes impossible for Congress to "end US manned spaceflight" without outright legally prohibiting it.

Which is even less likely than NASA getting the funding it needs for its bloatware lunar architecture.