"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.
McCain lashed out at Obama's personal history despite Obama's repeated praise of McCain's military service. As Obama said Tuesday night in Des Moines, Iowa: "We face an opponent, John McCain, who arrived in Washington nearly three decades ago as a Vietnam War hero, and earned an admirable reputation for straight talk and occasional independence from his party."
McCain was a Navy fighter pilot who was shot down and spent nearly six years as a Vietnam prisoner of war. At age 46, Obama is too young to have been drafted or fought in Vietnam. The direct U.S. military involvement in the Vietnam War officially ended in 1973, the same year the military draft was ended and replaced by an all-volunteer military.
The candidates' criticism of each other has grown increasingly acrimonious in recent weeks, a sign of things to come in the general election campaign.
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 passed the measure, sponsored by Sen. Jim Webb, D-Va., and supported by Obama, on Thursday by a 75-22 vote as 25 Republican abandoned President Bush, who opposed the provision.
Obama and his rivalreturned to Washington for the vote. McCain skipped the vote to campaign and raise money in California.
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 completing only one enlistment even as the U.S. fights two wars and is trying to increase the size of the Army and Marine Corps.
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.
"Most worrying to me is that by hurting retention, we will reduce the numbers of men and women who we train to become the backbone of all the services, the noncommissioned officer," McCain said in his statement.
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."
McCain, in his statement, accused Obama of being motivated by politics.
"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."