The number of Colorado parents eligible to receive the federal Child Tax Credit could be cut by nearly 70% if congressional Democrats and the Biden administration cave to the demands of one of their Democratic colleagues, according to a new report.

The vast federal program – which sends monthly payments to parents of children 17 years old and younger – has been a top policy priority of U.S. Sen. Michael Bennet since the middle of the last decade and was signed into law by President Joe Biden in March as part of a pandemic response package.

The credit is in place for the 2021 tax year and the Denver Democrat has lead the way on proposing a five-year extension as part of the $3.5 trillion budget reconciliation package making its way through Congress. But Bennet’s Democratic colleague U.S. Sen. Joe Manchin (D-W.Va.) is targeting the CTC in an effort to cut the top line figure for the reconciliation package down by some $2 trillion.

With the Senate locked at 50-50, Democrats in that chamber need their entire voting block to stick together for Vice President Kamala Harris to cast the tie-breaking vote. That gives the West Virginia Democrat, along with Arizona Democratic U.S. Sen. Kyrsten Sinema, outsized influence over negotiations on the reconciliation package, which contains much of Biden’s domestic agenda.

Axios on Sunday reported Manchin is flexing that influence, telling the White House “the child tax credit must include a firm work requirement and family income cap in the $60,000 range.”

Researchers at the self-proclaimed “moderate” Niskanen Center, a Washington, D.C.-based think tank, on Tuesday released estimates based off of Axios’ report showing if Manchin got his way, some 37.4 million children across the country would lose out on federal aid.

Colorado would be particularly hard hit based on the projections put together by the Niskanen Center’s Robert Orr and Samuel Hammond.