U.S. Sen. Claire McCaskill, D-Mo., told several hundred at Barack Obama’s Midtown campaign headquarters Thursday night that she’s committed to spending the next four weeks focused primarily on winning Missouri for Obama.

“I will be in Missouri from now until Election Day,” McCaskill said. “I’ll be standing shoulder to shoulder with you.”

McCaskill had brought a huge sheet cake (baked by McArthur Bakery in Kirkwood) that was adorned with the Obama campaign symbol and his “Change” slogan.

The cake and the rally were to mark the actions on Oct. 9, 2004, when then-Democratic nominee John Kerry and the Democratic National Committee closed down shop in Missouri and ceded the state to the GOP incumbent, President George W. Bush.

“Noone in this room remembers four years ago today like I do,” said McCaskill, who was running for governor at the time against Republican Matt Blunt.

“All of the sudden, our get-out-the-vote effort was fulled out from under us. Literally hundreds of campaign workers left the state.”

This time, said McCaskill, Obama’s campaign operation is booming in the state, and he’s neck-and-neck in the latest state polls against Republican John McCain.

And Obama running mate Joe Biden is touring the state, and even stopping Friday for a rally in Springfield, Mo.

“Our rallies are about hope. Our rallies are about lifting up,” said McCaskill, taking note of the angry jeers and verbal attacks at McCain’s recent events.

Afterwards, McCaskill said in a brief interview that she was mystified why McCain was launching personal attacks at Obama  when the financial markets are spiraling downward. “It’s a scary time,” she said. “That’s why it’s more important that we talk about real issues.”