Democrats say they'll 'fight tooth and nail' to keep programs like the child tax credit from falling out of Biden's big bill. Here's what Joe Manchin's Build Back Better could look like.

• Democrats are racing to keep Sen. Joe Manchin from killing top priorities like the child tax credit.
• Manchin said negotiations over Biden's agenda are set to restart "from scratch."
• He's signaled a willingness to strike a deal on climate measures; here's what else could get his thumbs-up.

Democrats spent much of January on a failed effort to pass voting rights legislation, a top priority in the party. With the endeavor now in shambles, they're refocusing their attention on passing a scaled-back version of their Build Back Better legislation — perhaps in "chunks" as President Joe Biden suggested.

But they're running into a familiar obstacle: Sen. Joe Manchin of West Virginia. Without his vote, Senate Democrats can't approve the plan over unified GOP opposition.

Manchin told Insider on Thursday that any future negotiations with the White House would be "starting from scratch." It raises the prospect that legislation would take several more weeks or even months to clear the 50-50 Senate with only Democratic votes.

That means a whole new round of Democrats working to figure out what parts of their domestic agenda Manchin is willing to support. 

Some programs like the expanded child tax credit are at risk of falling out of the bill due to objections from Manchin. "We're gonna fight tooth and nail to keep it in," Sen. Michael Bennet of Colorado, an advocate of the program, told Insider.

Here's what could get a thumbs-up from Manchin as Democrats grapple to keep top priorities from falling out of the Biden spending bill.

Obamacare fixes and prescription drug price controls

The House bill included a fresh boost of federal subsidies so people could better afford private health coverage from marketplaces established under the Affordable Care Act. It would last through 2025.

An extension of the program was part of Manchin's offer to the White House, The Washington Post reported. Many Democrats support the initiative since it would widen who qualifies for health coverage to many more in the middle-class, either cutting or scrapping monthly premiums depending on their income. The federal assistance was beefed up for a year under the Biden stimulus law and it's slated to expire at the end of 2022 if Congress doesn't step in.

Many in the party, including Manchin, also want to empower the federal government to negotiate the prices of at least some prescription drugs. Key provisions within the plan include a cap on insulin prices set at no more than $35 a month and other limits on out-of-pocket spending, per the Kaiser Family Foundation.

He told reporters last week that he seeks to address "pharmaceuticals that are gouging the people with high prices," adding, "we can fix that."

Universal pre-K

Another central component of the legislation is a measure to establish universal pre-K for every three and four-year old in the US.

It's a program that Manchin previously said he's "all in" on. Part of the reason could be that this program is already a reality in West Virginia for every four-year-old, The New York Times reported.

However, the initiative's effectiveness would hinge on whether states actually participate in it. That may be a problem due to its funding formula which would see states picking up a hefty part of the tab to create or expand existing programs down the road. In addition, GOP states may simply opt out, The Washington Post reported. 

$500 billion in climate spending

Democrats increasingly view the Build Back Better bill as their last chance to enact sweeping measures to mitigate the heating of the planet. The US has recently experienced a spate of wildfires, strong storms, and droughts that were likely more severe due to the climate emergency. 

Much of the legislation is devoted to a series of tax credits and incentives meant to smoothen the transition from fossil fuels to cleaner energy sources like wind and solar power. One part of the bill sets aside funding for electric vehicle buyers to get up to $12,500 in tax credits.

Manchin appears to favor that chunk of the bill over the rest. "The climate thing is one that we probably can come to an agreement much easier than anything else," he said on Jan. 4. "There's a lot of good things in there."

Biden has said he believes that part of the package could be salvaged. "I think it's clear that we would be able to get support for the $500 billion plus for energy and the environment," he said last week.