Days ago it was fashionable to dismiss warnings of a default by the US government as scare talk. after a nail-biting moment, Republicans opposed to raising the debt ceiling would back down and a last-minute compromise would enable everyone to relax. But as the wrangling continues in Washington, and Tuesday's deadline looms, a solution that enables Barack Obama's administration to pay its bills is looking as if it might not materialise.  One problem is that it's no longer clear that there are just two sides to this dispute. While Democrats want the debt limit lifted far enough to allow the crisis to be pushed beyond the 2012 presidential election, the fractured Republicans barely agree on a way ahead. Last night the Republican House leader, John Boehner, scrambled to put together an alternative Republican plan, cutting spending by $900bn in the longer term while temporarily raising the debt limit for a few months.  as a sop to the Tea Party, whose supporters torpedoed a similar bill on Thursday, Mr Boehner tacked on an absurd-sounding proposal making the package contingent on a constitutional "balanced budget" amendment, which would then of course have to go to the states for ratification. as that will be wholly unacceptable to the Democrat-controlled Senate, it is not clear that the passage of Mr Boehner's plan brings a resolution of the crisis before Tuesday much closer. If the logjam has moved at all, it is by an inch.  Just possibly House and Senate will discover some hitherto invisible piece of common ground, b