For the fourth time this summer Republicans stopped the Senate from taking up wide-ranging legislation that extends tax breaks for teachers, businesses and parents and provides tax credits to an array of renewable energy entrepreneurs.

Major business groups, usual GOP allies, have implored Congress to act on the tax credits, many which expired at the end of last year or will run out at the end of this year. But for many Republicans, it's a matter or principle and politics: many oppose what they say are new tax increases to pay for parts of the package and nearly all say the Senate's only business now is acting on an energy bill that promotes drilling and other measures to boost domestic oil supply.

The White House, citing new taxes and other objections to the bill, threatened a presidential veto. The vote Wednesday was 51-43, nine short of the 60 needed to begin floor debate.