Centrist Democrats disagree with Obama's plan to increase spending on most domestic programs by about 9 percent next year. They want no spending increase.

Congress has to "develop a realistic plan for putting our country back on a path to fiscal responsibility," said Rep. Charlie Melancon, D-La., a leader of the moderate Democratic Blue Dog Coalition. "It is vital that we begin working to bring our books back to balance, using tools such as (mandatory) pay-as-you-go budgeting."

Blue Dogs were careful not to criticize Obama, but said they've felt little pressure from the canvassing.

Rep. Melissa Bean, D-Ill., once a coalition member but now vice-chair of the New Democrat Coalition, said she wasn't aware of the effort and has heard no response to it from her district.

Meanwhile, established liberal groups are gearing up to stop the Blue Dogs in more traditional ways. The Campaign for America's Future and other groups have scheduled a joint news conference for Tuesday to announce what they term a "new campaign to dog the Blue Dogs."

In a statement, they said that "President Obama is back in campaign mode as he pushes for a budget proposal that has faced opposition from a group of Democratic senators led by Sen. Evan Bayh," a moderate from Indiana.

In addition, Obama is expected to tout his budget on Tuesday night in a prime-time news conference.