Republican John McCain, a Vietnam War hero who hopes to be commander in chief, said Thursday that Democrat Barack Obama had no right to accuse him of political posturing on military scholarships because the Illinois senator did not serve in uniform.

"And I will not accept from Senator Obama, who did not feel it was his responsibility to serve our country in uniform, any lectures on my regard for those who did," the Arizona senator said in a harshly worded statement issued Thursday.

At issue is an expansion of the GI bill that would guarantee full college scholarships for those who serve in the military for three years. The Democratic-led Senate on Thursday passed the measure, sponsored by Sen. Jim Webb, D-Va., and supported by Obama, on a 75-22 vote as 25 Republicans abandoned President Bush, who opposed it.

Obama and his rival, Sen. Hillary Rodham Clinton, returned to Washington for the vote. McCain stayed in California to campaign and raise money.

McCain opposes the measure, as does the Pentagon, out of concern that providing such a benefit after only three years of service would encourage people to leave the military after only one enlistment even as the U.S. fights two wars and is trying to increase the size of the Army and Marine Corps. McCain said he worries it would reduce the number of noncommissioned officers.

Instead, McCain and Republican colleagues proposed a bill to increase benefits in conjunction with a veteran's length of service. Senate Democrats blocked the measure last week.

While McCain was joined on the campaign trail in California by Gov. Arnold Schwarzenegger, former Gov. Pete Wilson and former eBay CEO Meg Whitman, Obama reiterated his respect for McCain's service in a speech on the Senate floor.

"He is one of those heroes of which I speak," Obama said. "But I can't understand why he would line up behind the president in his opposition to this GI bill. I can't believe why he believes it is too generous to our veterans. I could not disagree with him and the president more on this issue. There are many issues that lend themselves to partisan posturing, but giving our veterans the chance to go to college should not be one of them."

In his statement, McCain lashed out at Obama for questioning his motives.

"Perhaps if Senator Obama would take the time and trouble to understand this issue, he would learn to debate an honest disagreement respectfully," McCain said. "But, as he always does, he prefers impugning the motives of his opponent, and exploiting a thoughtful difference of opinion to advance his own ambitions." Continued...