Republican Rick Perry says he's dropping out of the GOP presidential race and endorsing Newt Gingrich.

President Barack Obama vowed to delay Congress' year-end vacation as well as his own Thursday for "as long as it takes" to extend Social Security payroll tax cuts and long-term jobless benefits, his second challenge in as many days to conservative Republicans.

House Republicans intend to propose a gradual increase in Medicare premiums for wealthy seniors to help cover the cost of renewing Social Security payroll tax cuts and benefits for the long-term unemployed, officials said Wednesday.

President Barack Obama accepted a move by Senate Democrats to scale back his Social Security payroll tax cut extension on Monday, then prodded Republicans to support it despite a requirement for the very wealthy to pay more taxes.

Courting disaffected conservatives, House Republican leaders offered Friday to overturn a pair of Obama administration environmental policies and avert a deep cut in payments to doctors treating Medicare patients as part of legislation renewing a Social Security payroll tax cut through 2012.

Senate Republicans on Thursday defeated a plan by President Barack Obama to renew a temporary cut in the Social Security payroll tax, even as all sides on Capitol Hill continue to promise an eventual compromise on a tax holiday before Congress leaves Washington for Christmas.

House Republicans are drafting legislation to renew an expiring unemployment benefits program, officials said Thursday, and intend to add it to a planned extension of a Social Security payroll tax cut due to run out on Dec. 31.

Republican congressional leaders stressed a willingness Wednesday to extend a Social Security payroll tax cut due to expire Dec. 31, setting up a year-end clash with Democrats over how to pay for a provision at the heart of President Barack Obama's jobs program.