McConnell did not support the President Joe Biden's law, which passed with only Democratic votes. One of its social programs made him uneasy.

According to a forthcoming book, "This Will Not Pass", McConnell was unnerved by the expanded child tax credit. It was obtained by Insider before the May 3 release.

After the law was passed, a Kentucky Republican told a friend that it was too popular for Republicans to take it back if they regained control of Congress.

If Americans grew used to the benefits of the new law, McConnell suggested, it would be difficult for Republicans to repeal popular measures.

A person for McConnell did not respond to a request for comment.

The child tax credit expired due to opposition from Sen. Joe Manchin of West Virginia. Democrats wanted to extend it for a year. The House bill was sunk by Manchin due to his resistance to the benefit.

The child allowance is unlikely to be revived anytime soon according to Biden. Manchin tried to squash any attempt to revive social spending initiatives in a smaller version of the bill. Democrats are trying to pass a smaller package with his approval in the Senate.

Schumer Manchin
Senate Democrats huddle with Sen. Joe Manchin.
Drew Angerer/Getty Images

The child tax credit has been transformed into a one-year cash benefit for families, widening eligibility to the poor for the first time. Families received between $250 and $300 for each child under the age of 5.

The Center on Poverty and Social Policy at Columbia University found that the overhauled program reduced child poverty by about a third. The gains were erased a month after the program ended. Child poverty has gone up.

Families that spoke to Insider said they used the federal cash to cover basic expenses like groceries and utility bills. The aid recipients supported it, though it never gained widespread popularity among voters.

Manchin didn't seem to accept the child allowance. He was skeptical about the federal government sending monthly checks to families with no strings attached.

According to the authors, the conservative Democrat privately complained to his colleagues that the enhanced child tax credit would pay people to have more kids when West Virginia families couldn't afford them.

Manchin told Booker that the money would be spent on drugs. Booker was told by authors Martin and Burns that families would use it on everyday expenses like diapers.

Democrats are worried about a big win in the November elections due to rising prices. According to a survey released last month, Republicans are edging out Democrats among parents who used to get the child tax credit.