Newt Gingrich, writing in the Washington Post's "Topic A," sees Arlen Specter's party switch in exactly the right light, I think:

Arlen Specter's decision to leave the Republican Party in name as he left it in spirit over the stimulus vote is further proof that high taxes, big spending and big government are unacceptable to Republican voters.

This switch is a function of personal survival and will make clearer the profound difference between the Democratic Party of big government, big bureaucracy, high taxes and big unions and the Republican Party of lower taxes, less bureaucracy and small business, with its emphasis on the work ethic, civil society and local control back home.

When congressional Republicans forgot that their party was the party of taxpayers and government reformers, they lost control in 2006. When they accepted the Bush big-spending plans of 2008, they further lost ground.

When Sen. Specter voted for a $787 billion big-spending bill no elected official had even read, he widened the gap between himself and the tax-paying small-government conservatives who are the base of the Republican Party.