A proposal for federal paid family leave is at risk of ending up on the chopping block as Washington lawmakers work to finalize new social spending legislation.

Cutting the plan out of the Build Back Better package could cripple Democrats’ chances in key Senate races next year, advocates warn.

Eight states will have battleground contests between Republicans and Democrats in 2022, according to recent research from Global Strategy Group, a Democratic polling firm, and Paid Leave for All Action, an advocacy organization. That includes Arizona, Florida, Georgia, Nevada, North Carolina, New Hampshire, Pennsylvania and Wisconsin.

“These states will decide control of the Senate and could go either way,” the research notes.

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Ensuring paid leave for all U.S. workers with serious illnesses or caring for a new child or seriously ill family member ranks second as a priority among voters in the Build Back Better package, Global Strategy Group and Paid Leave for All Action’s polling shows. Allowing Medicare to negotiate prescription drug prices and cover hearing benefits came in first.

“Paid leave is not only among the top-performing policies; it is on par with what everyone considers to be the most important policies,” said Joey Teitelbaum, lead researcher on battleground polling at Global Strategy Group, at a Tuesday webinar comprised of Democratic strategists and pollsters.

Lawmakers are looking to pass the Build Back Better plan along party lines through a process known as reconciliation, which would require support from all Democratic lawmakers in the Senate. The House of Representatives passed the legislation last month exclusively with Democratic support.

One big obstacle for Senate Democrats may be the opposition of Sen. Joe Manchin, D-W.V., who has said he will not back the proposal due to cost concerns.

The tally for the Build Back Better package is roughly $1.75 trillion. The Congressional Budget Office estimates the four-week paid leave proposal would cost around $205 billion over 10 years.

New survey data from Global Strategy Group and Paid Leave for All Action also found strong support for paid leave in West Virginia, with 80% of the state’s voters backing paid medical leave and 75% for paid family leave.

“This is not really a policy anymore for Democrats; it’s a core value,” said Celinda Lake, president of Lake Research Partners, a public opinion and political strategy research firm, during Tuesday’s webinar.

“So if you want to prove that you are a Democrat and you want to prove that you share people’s family values, paid family and medical leave is a very, very powerful issue to do that,” she said.

Supporting paid leave could help candidates draw women voters, particularly suburban and non-college educated women who will be crucial to both parties’ victories in 2022, Teitelbaum said.

It remains to be seen whether Manchin will change his mind, though advocates at the webinar expressed hope he could be swayed.

Research from the Bipartisan Policy Center points to potential room for compromise. The costs associated with the proposal may be substantially reduced if the plan were revised to include just paid parental leave. Another cost cutting option would be means testing for eligibility.

“There’s not a lot of conversation about how you could play with dials that are different than just the number of weeks to get a pretty robust program for a minimal cost,” said Adrienne Schweer, a fellow at the Bipartisan Policy Center and lead of its paid family leave task force.

Republicans have supported a different approach that would create incentives for employers to provide paid leave benefits through a bill called the Protecting Worker Paychecks and Family Choice Act. Republicans on the House Ways and Means Committee have touted a poll showing that 49% of voters would back that plan over Democrats’ proposal.

“Republicans’ approach to child care and paid leave puts families and Main Street businesses first, while Democrats’ one-size-fits-all socialist solution gives Washington control,” said Rep. Kevin Brady, R-Texas, in a statement.