The committee went after Sens. Bill NelsonClarence (Bill) William NelsonGillum holds razor-thin lead in Florida race Senate panel wants Hyundai, Kia to answer over reported engine fires Election Countdown: Dems outraise GOP in final stretch | 2018 midterms already most expensive in history | What to watch in second Cruz-O'Rourke debate | Trump raises 0M for reelection | Why Dems fear Avenatti's approach MORE (Fla.), Ben Nelson (Neb.), Claire McCaskillClaire Conner McCaskillMcCaskill calls on GOP opponent to appoint special prosecutor to look into undercover video Dems go on offense against GOP lawsuit on pre-existing conditions Credit union group to spend .8 million for vulnerable Dem, GOP incumbents MORE (Mo.), Sherrod BrownSherrod Campbell BrownOn The Money: Deficit hits six-year high of 9 billion | Yellen says Trump attacks threaten Fed | Affordable housing set for spotlight in 2020 race Lawmakers, Wall Street shrug off Trump's escalating Fed attacks The Hill's Morning Report — Presented by PhRMA — Dem victories in `18 will not calm party turbulence MORE (Ohio), Debbie StabenowDeborah (Debbie) Ann StabenowElection Countdown: Dems outraise GOP in final stretch | 2018 midterms already most expensive in history | What to watch in second Cruz-O'Rourke debate | Trump raises 0M for reelection | Why Dems fear Avenatti's approach Republican Senate candidate apologizes after swastika spotted in campaign ad Poll: Dem Stabenow has 9-point lead over Republican James in Michigan Senate race MORE (Mich.), Joe ManchinJoseph (Joe) ManchinTrump Jr. to campaign in West Virginia for Manchin challenger Dems go on offense against GOP lawsuit on pre-existing conditions Credit union group to spend .8 million for vulnerable Dem, GOP incumbents MORE (W.Va.), Tester and Casey in news releases Monday. 

Ben Nelson, a top GOP target in 2012, expressed some disappointment Monday with the president's plan. In a statement, Nelson said the budget proposal "starts the debate about getting spending under control in Washington," but lamented that some of the largest reductions in the plan Obama said would reduce the deficit by $1 trillion over the next decade "arrive in the later years."  

Nelson said he intends to work with senators to "enact spending cuts that kick in sooner," but he didn't offer any detail on specific cuts.

Bill Nelson praised the budget proposal Monday, blasting critics whom he said "offer no real solution and really haven't done any cutting themselves."

"At least the president's budget is a step in the right direction in trying to get this country turned around, to really do something about lowering the deficit and cutting all of this wasteful spending," Nelson told the Bradenton Herald

Brown pointed the finger at Republicans, calling the proposal an effort to "clean up after years of reckless decisions that exacerbated our budget crisis," mentioning the Bush-era tax cuts and wars in Iraq and Afghanistan. 

"By not turing our backs on priorities that promote America's competitiveness — like education, innovation, infrastructure and energy — the proposal is forward-looking and responsible," said Brown.  

No reaction yet to the president's plan from McCaskill or Manchin, both top 2012 targets.  

McCaskill has been championing a plan, along with Sen. Bob CorkerRobert (Bob) Phillips CorkerCorker: Trump administration 'clamped down' on Saudi intel, canceled briefing GOP leaders hesitant to challenge Trump on Saudi Arabia Poll: GOP's Blackburn holds slim lead in Tennessee Senate race MORE (R-Tenn.), to enact a federal spending cap that she says will cut some $8 trillion from the deficit over the next decade.