WASHINGTON - Democrats and Republicans sparred Sunday over recently released documents showing the White House helped craft talking points for Susan Rice, former U.N. ambassador, after the 2012 attack on a U.S. diplomatic compound in Benghazi, Libya.

House Republicans last week said they would form a select committee to investigate the Obama administration's response to the incident, which occurred less than two months before the last presidential election.

Democrats said calls for further investigations are politically motivated.

Rep. Adam Schiff (D., Calif.), on Fox News Sunday, called the GOP effort a "colossal waste of time," noting four bipartisan probes have taken place. He said Democratic leaders should not appoint anyone to the panel. "It's just a tremendous red herring and a waste of taxpayer money," he said

Former Sen. Rick Santorum (R., Pa.), backed the decision by Republican leaders, saying on ABC's This Week that they have an obligation to investigate the Benghazi matter.

"There's a firestorm . . . across America among Republicans who don't think we've taken this issue on," he said, adding that House Speaker John Boehner (R., Ohio), has "no choice but to move forward on this."

Rice appeared on several talk shows after the incident attributing the assault to an anti-Muslim video that sparked spontaneous protests - the administration later retracted that theory.

An e-mail released under court order last week shows that Ben Rhodes, one of President Obama's top advisers, had outlined talking points for Rice to discuss protests across the Middle East. Rhodes called on her to "underscore that these protests are rooted in an Internet video, and not a broader failure of policy."

Republicans say the message proves the administration misled the public to save face. They have questioned why the State Department did not supply the Rhodes memo after the House oversight committee's chairman, Darrell Issa (R., Calif.), subpoenaed all documents related to the Benghazi response.

White House press secretary Jay Carney has said the administration did not initially hand over the document because it did not relate to the attack.