In national news, Democrat Barack Obama plunged Wednesday into a five-month election battle with Republican John McCain after making history by becoming the first black presidential nominee of a major US party. The Illinois senator's giant-killing win over Hillary Clinton came at the climax late Tuesday of the longest, most expensive and spellbinding nominating epic ever. Clinton has not yet conceded the race, but on Wednesday she held out an olive branch to Obama after he clinched the number of delegates needed to be the Democratic party's presidential nominee in the November elections. "Let me be very clear, I know that Senator Obama will be a good friend to Israel," she told a powerful pro-Israel lobby group. But the former first lady stopped short of formally abandoning her quest to be the first woman elected to the Oval Office, and although they both addressed the gathering within minutes of each other they had no plans to meet. Instead as President George W. Bush joined worldwide plaudits of Obama's stunning success, Clinton's supporters strove to coax the new Democratic standard-bearer into choosing her as his running mate. Together, they would be "unstoppable," the New York senator's campaign chairman, Terry McAuliffe, told MSNBC television. "I think we would have the White House for 16 years." On November 4, voters must pick between Obama, 46, a freshman senator and charismatic mixed-race standard-bearer of a new political generation, and McCain, 71, a Vietnam war hero asking for one final call to service. Clinton has said she will now consult with supporters and party leaders on the way forward.