BOCA RATON, Fla. — Barack Obama [1] went to a synagogue in South Florida on Thursday to pledge unwavering support for Israel's security as he sought to assuage Jewish concerns about his foreign policy views and strengthen his support within a crucial Democratic constituency in this swing political state.

The Illinois senator, the leading Democratic presidential contender, provided assurances of traditional positions on relations with Israel, promising an "unshakable commitment" to its security, praising the bond between the U.S. and Israel and declaring he would not negotiate with Hamas and Hezbollah, groups the U.S. considers terrorist organizations.