Some of the most prominent and respected handicappers can now envision an election in which Democrats suffer double-digit losses in the House — not enough to provide the 40 seats necessary to return the GOP to power but enough to put them within striking distance…

Turnout levels may also work in the GOP’s favor: House Democrats who narrowly won election in 2008 on the strength of high turnout among African-Americans and young voters probably won’t be able to count on that same level of enthusiasm next year in a nonpresidential election…

Silver also pointed to the role of health care legislation, which he said is increasingly looking like a no-win situation for House Democrats.

In his view, if a compromise bill is passed without a public option, the liberal base will become upset and may not be enthusiastic heading into the 2010 midterm elections, where their support will be critical. But if Democrats pass legislation without any assistance from Republicans, the party risks incurring the wrath of independent voters looking for a bipartisan solution. And if no health care reform at all gets passed, the administration and vulnerable members will have spent political capital without getting any results on the administration’s signature issue.