"I looked at the president’s proposed budget, the projected deficits, the accumulated debt over the next decade — and wondered: what are we doing?" said Manchin. 

So far most Senate Democrats have refrained from even mentioning the budget, which Senate Majority Leader Harry ReidHarry ReidThe Memo: Trump pulls off a stone-cold stunner The Memo: Ending DACA a risky move for Trump Manchin pressed from both sides in reelection fight MORE (D-Nev.) indicated he would not call up for a vote. Only Assistant Senate Majority Leader Dick DurbinRichard (Dick) Joseph DurbinSenate Dems hold floor talk-a-thon against latest ObamaCare repeal bill Overnight Defense: Senate passes 0B defense bill | 3,000 US troops heading to Afghanistan | Two more Navy officials fired over ship collisions Senate passes 0B defense bill MORE (D-Ill.) offered guarded support on Tuesday, saying it offered "fiscal responsibility on one side and economic growth on the other."

Republicans, in the meantime, have burned hours of floor time trying to lampoon it and suggesting that if it were called up for a vote it would likely face the same fate as last year’s budget, which was killed 97-0. 

Manchin went on to argue the proposal was deceptive in its claim to balance the budget.

"There is not a single year that this budget is balanced," he said. "At the end of a decade, this budget puts us an additional $6.7 trillion in debt. How does that make sense?"

Manchin, a centrist, went on to cover his flank, however, affirming he was a "proud Democrat" and characterizing his critique as “respectful as possible.” 

“I can already hear some folks say: ‘Oh, there goes Joe ManchinJoseph (Joe) ManchinGOP sees fresh opening with Dems’ single payer embrace Trump steps up courtship of Dems The Hill's 12:30 Report MORE again, blaming President Obama …' but what we’re doing just doesn’t make any sense to me, and I certainly can’t in good conscience try to tell the people of West Virginia any different,” he said. 

“If and when the president’s budget proposal comes up for a vote, I will not support it,” he concluded.