Joe Manchin indicated he would cut a Democratic-only infrastructure plan to $2 trillion so it doesn't grow the national debt

• Manchin said Sunday he would support a $2 trillion Democratic-only infrastructure plan.
• Senate Democrats are weighing up to $6 trillion in new spending, and Manchin may derail their ambitions.
• "I do not want to add more debt on," Manchin said on ABC's "This Week."

Sen. Joe Manchin said Sunday that he could support a $2 trillion Democratic-only infrastructure plan. It suggests Senate Democrats may have to significantly curtail their ambitions to earn Manchin's vote.

The influential senator pushed back on the $6 trillion price tag for a potential plan drafted by Sen. Bernie Sanders and Senate Democrats. It includes provisions to expand Medicare and expand the child tax credit among others.

But Manchin suggested it could be cut so it can be fully paid for with tax increases and no deficit-spending.

"I want to make sure we pay for it," Manchin said on ABC's "This Week." "I do not want to add more debt on."

-This Week (@ThisWeekABC) June 27, 2021

He also emphasized his willingness to roll back the 2017 Republican tax law, which slashed corporate taxes to 21%.

"I'm willing to go to 25," Manchin said, referring to hiking the corporate tax rate. "I think that basically capital gains should be 28 percent, not at 21. There's changes we can make that still keep us competitive."

His comments come a day after President Joe Biden reversed course from a threat he made Thursday to veto a $1 trillion bipartisan infrastructure plan if a party-line package didn't clear Congress. They triggered an uproar from Senate Republicans who complained that was never part of their agreement.

"I gave my word to support the infrastructure plan, and that's what I intend to do," Biden said in a statement on Saturday.

Democrats have long said they're operating on two-tracks to approve a separate spending plan without the GOP alongside the bipartisan package. The latter measure will provide $600 billion in fresh spending concentrated on physical parts of the economy like highways and bridges.

Republicans who negotiated the plan appeared to be back onboard Sunday. "I am glad they have now been de-linked and we can move forward with a bipartisan bill," Sen. Rob Portman of Ohio told ABC's "This Week."

Democrats are poised to push ahead with another plan using an arduous legislative process known as reconciliation. It only requires a simple majority vote in the Senate and shields budgetary bills from the 60-vote threshold.

Biden's legislative path ahead is one fraught with peril, given his party's narrow control of the House and the Senate split 50-50. Senate Democrats must stick together for a follow-up plan focused on social initiatives to clear the evenly-divided chamber.

Manchin hasn't pledged to vote for a party-line package, and only said he would consider supporting a plan after it's fully drafted. "We have to look at reconciliation," he told Insider on Thursday.