"I've got a real problem about expanding this war where the rest of the world is sitting around and saying, 'Isn't it a nice thing that the taxpayers of the United States and the U.S. military are doing the work that the rest of the world should be doing?'" Sanders said on ABC's "This Week."
"I have a real problem supporting 30,000 or 40,000 more troops and $100 billion more a year for that war on top of what we're spending in Iraq," he said.
Sen. Carl Levin, D-Mich., said he doubts Obey's war tax will pass, but placed a different condition on the worth of an anticipated troop surge.
"It's worth it, providing our mission is to get the Afghan army and the Afghan people in charge of their own future. We cannot by ourselves win a war," Levin said on CBS's "Face the Nation." He also said the president should address how to pay for a surge in a "very forthright way."
However, not all Democrats are critical of an anticipated troops increase in Afghanistan.
"I'm looking foward to hearing the presidents's rationale for choosing the strategy that he has. I think he's going to adopt the optimal strategy," said Sen. Evan Bayh, D-Ind., on "FOX News Sunday."
Bayh said he would like to hear the president be forthright about the costs of his decision, but said it was important to priortize national security over fiscal health.
"You need to provide for the nation's security regardless of your financial situation, and there's no bigger deficit hawk in Congress than I am," Bayh said.
Republicans who support increased spending in Afghanistan say the president should sacrifice spending on Democratic-backed health care reform.
Sen. Richard Lugar, R-Ind., ranking member of the Foreign Relations Committee, said Congress should focus on the Afghan war instead of health care reform for the remainder of the year.
"The war is terribly important. Jobs and our economy are terribly important. So this may be an audacious suggestion, but I would suggest we put aside the health care debate until next year, the same way we put cap-and-trade and climate change and talk about the essentials, the war and money," Lugar said.
And Sen. Lindsey Graham, R.-S.C., said he saw no better use of taxpayer dollars than to defend America.
"Can we trim up the health care bill and other big-ticket items to pay for a war that we can't afford to lose?" Graham said on ABC.
Despite the costs of health care reform, Reed and other Democrats said the president should push forward.
"I think we have to push forward. I think the president's speech will be appropriate. I think the strategy we'll analyze in the committees and I think we can go forward on both fronts and we have to," Reed said.
Levin predicted Majority Leader Sen. Harry Reid would garner 60 votes in the Senate to pass a health care reform bill, "probably" with a public option that includes the possibility for states to opt out.
"I think there's a decent chance that we'll be able to get 60 votes," he said on CBS. "The leader here, Harry Reid, has done a really good job of getting 60 votes to jump that first hurdle, which was a procedural hurdle. But I wouldn't underestimate his capability to get us to 60 votes on final passage."