Democratic presidential candidate Barack Obama ratcheted up his argument with US President George W. Bush over policy toward Iran on Friday, slamming Bush for comments he made in Jerusalem a day earlier and attacking Republican rival John McCain for his policy on Hamas.Obama began a campaign stop in South Dakota, home of an upcoming primary, by giving a lengthy denunciation of the comments Bush had made on Thursday warning against talking to terrorists and radicals.Obama interpreted that as an attack on himself, since he has indicated he would engage in direct talks with Iran and other rogue countries if elected president."Yesterday, George Bush was before the Israeli parliament, the Knesset, to help commemorate the 60th anniversary of Israeli independence. That's a wonderful occasion and a time for celebration," Obama began. "But instead of celebrating and offering some clear ideas about how to move the situation in the Middle East forward, the president did something that presidents don't do, and that is launch a political attack targeted toward the domestic market in front of a foreign delegation."The White House has denied that the remarks were aimed at Obama. In his Knesset speech, Bush re-articulated his long-standing policy of not talking to rogue actors. In doing so, he lambasted this approach as "the false comfort of appeasement, which has been repeatedly discredited by history."He also said, "We have heard this foolish delusion before. As Nazi tanks crossed into Poland in 1939, an American senator [Idaho Republican William Edgar Borah] declared: "Lord, if I could only have talked to Hitler, all this might have been avoided."On Friday, White House counsel Ed Gillespie said there was some concern the remarks would be interpreted as a dig at former president Jimmy Carter, who recently met with the Hamas leadership, but that neither he nor Obama had been the target of Bush's criticism.Nevertheless, a host of leading Democrats considered the president's remarks an attack on Obama and attacked Bush for involving himself in the current campaign, something the president has vowed not to do.In his comments in South Dakota Friday, Obama tied Bush's position to that of McCain, the presumptive Republican nominee. The contours of Obama's attack - and his effort to make the names Bush and McCain synonymous - seemed an indication of his game plan going into November should he win the Democratic nomination, as seems increasingly likely.In addition to seeking to tie McCain's stance to that of Bush, Obama also suggested he would try to turn the tables on the Republican critique of his own approach, labeling GOP policies "naÃ¯ve," a word that's been used to attack Obama."They're going to have to explain why Hamas now controls Gaza, Hamas that was strengthened because the United States insisted that we should have democratic elections in the Palestinian Authority," he said, referring to Bush and McCain. "They're going to have to explain why it is that Iran is able to fund Hizbullah and poses the greatest threat to America and Israel and the Middle East in a generation."He also argued that McCain's assertion that he supported negotiating with terrorists was wrong."I have been adamant about not negotiating with Hamas, a terrorist organization that has vowed to destroy Israel and won't recognize them," he said.Obama then used the issue to attack McCain ashypocritical, after he was portrayed as having supported engagement with Hamas during a television interview conducted two years ago with James Rubin, who served in the Clinton administration and supports Democratic presidential candidate Hillary Clinton.In a column in Friday's Washington Post, Rubin relates McCain's answer to a question he asked about how America should deal with the then newly elected Hamas government: "They're the government; sooner or later we are going to have to deal with them, one way or another, and I understand why this administration and previous administrations had such antipathy toward Hamas because of their dedication to violence and the things that they not only espouse but practice, so... but it's a new reality in the Middle East. I think the lesson is people want security and a decent life and decent future, that they want democracy. Fatah was not giving them that."McCain's campaign, however, denied that the comments reflected support for dialogue with Hamas. Instead, McCain insisted Friday that he had "made it very clear" that his position the was that Hamas must first stop calling for Israel's destruction before it could be engaged, as quoted by The Associated Press.Obama, he charged, wanted to negotiate directly with Iran, which "is very clear about developing nuclear weapons... They are sponsors of terrorist organizations. That's a huge difference in my opinion."