Despite President Bush’s threat to veto a war funding bill with congressional add-ons, 25 Senate Republicans broke ranks and voted in favor of passing the bill, which added $97 billion worth of spending on top of the $165 billion earmarked for military operations in Iraq and Afghanistan through next spring.

Although the 75-22 vote surpassed Bush’s veto threshold, a war of words did break out on the Senate floor when Democratic presidential candidate, Sen. Barack Obama of Illinois, fired the first shot at his Republican rival, Sen. John McCain of Arizona. Obama took issue with McCain on his reluctance to sign on to a new GI Bill amendment proposed by Sen. Jim Webb, D-Va., which accounts for over $50 billion of the proposed funding.“I respect John McCain,” Obama said, “but I can’t understand why he’s lining up with the president to oppose this bill,” which provides funding and housing allowances for vets at private and public colleges. “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.”

Initially, Obama’s words were lost on McCain, who was not in the chamber and did not vote on the bill. Obama and his Democratic presidential rival, Hillary Clinton of New York, voted in favor of the bill. McCain, who had previously stated he did not support the new GI Bill and offered his own version, missed the vote due to campaign fundraising commitments in California.

Obama’s words eventually did traverse the country and McCain was quick to fire back a response:

“It is typical, but no less offensive that Senator Obama uses the Senate floor to take cheap shots at an opponent and easy advantage of an issue he has less than zero understanding of,” McCain said in a statement. “If Sen. Obama would take the time and trouble to understand this issue he would learn to debate an honest disagreement respectfully. 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. If that is how he would behave as president, the country would regret his election.”

McCain’s absence did not go unnoticed by the Howard Dean, chairman of the Democratic National Committee, who said in a statement yesterday: “America’s veterans and military families deserve better than a candidate who is willing to keep our troops in Iraq for 100 years, but refuses to take care of them when they come home.”

On the Iowa front, Sens. Tom Harkin and Chuck Grassley voted along party lines. Harkin voted in favor of the bill while Grassley held the party line and joined 21 other Republicans in opposition to the funding bill.

“A supplemental appropriations bill is intended to pay for items of necessity like supporting our troops in the war on terrorism, which is something we can all agree on,” Grassley told the Iowa Independent in an email statement. “Instead, the majority decided to throw in everything but the kitchen sink and chose to ignore their own pay-as-you-go philosophy for most of the bill.

“I supported a GI Bill enhancement measure when it was offered as an amendment to another piece of legislation,” Grassley added. “But, because of procedural maneuvering, a GI Bill proposal was wrapped in with a package of unrelated spending and pet projects. It’s a shame we weren’t afforded the opportunity to give this important matter the separate consideration it deserves. In the end, this bill was riddled with a lot of troubling policy that I couldn’t support.”

Troubling or not, it remains to be seen what impact McCain’s non-vote will have on his presidential bid as he continues to court voters and fellow veterans. McCain will face his first test on the issue this Memorial Day weekend as Congress breaks for recess and the presidential candidates hit the campaign trail in full stride.