Sen. John Kerry warns in a new fundraising appeal that Republicans are intent on “swiftboating” President Obama in the same way that Kerry was attacked when he ran for president in 2004.

In an e-mail plea sent to Obama supporters Thursday, the Massachusetts Democrat points to a $3 million donation to a super PAC supporting Republican Mitt Romney from Bob Perry, a Texas homebuilder who helped fund the “Swift Boat Veterans for Truth” ads that questioned Kerry’s war record in 2004.

“I know all too clearly that these guys will do or say anything to win. They’ll stop at nothing,” Kerry says in the e-mail. “But forewarned is forearmed. Their multimillion-dollar smear tactics were new in 2004; in 2012 we know their playbook, and shame on us if we don’t tear it into shreds. Join me and we will stop the ‘swiftboating’ of President Obama.”...