A controversial bill on the Bush administration’s warrantless wiretapping program that won approval yesterday in the U.S. Senate split the votes of Iowa Sens. Tom Harkin and Chuck Grassley.

The bill overhauls rules on secret government eavesdropping and shields phone companies from lawsuits for their role in the program. Grassley, a Republican from New Hartford, sided with 69 other senators from both parties, including Democratic presidential nominee Barack Obama, in support of The Foreign Intelligence Surveillance Act (FISA). Harkin, a Democrat from Cumming, voted with 27 Democrats in opposition.

In supporting the bill, Grassley called the bipartisan passage of FISA an important step to ensuring law enforcement agencies have the tools they need to protect national security.

“This update [to FISA] is critically important to bring these tools up to date with today’s technology,” he said in a statement.

Grassley also emphasized that civil liberties had to be respected in the process.

Harkin said that while the intelligence community must have the tools they need to monitor and track terrorists, the rights of American citizens who have done nothing wrong must be protected.

“That is why I could not support this bill which does not appropriately safeguard the privacy rights of Americans – both at home and abroad,” he said in a statement. “Moreover, I could not support a bill that has the effect of granting immunity to telecom companies that knowingly violated the constitutional rights of Americans. Companies that broke the law should not get a free pass.”

The vote came two and a half years after public disclosure of the wiretapping program set off a fierce national debate over the balance between protecting the country from another terrorist strike and ensuring civil liberties.

More than 40 lawsuits have been filed in federal court charging major telecommunication companies, like AT&T Inc. and Verizon Communications, with violating customers’ privacy by conducting wiretaps at the White House’s direction without court orders.

This bill effectively ends those lawsuits. It is now on its way to the president, who has said he will sign it.