Sen. Mark Warner (D-Va.) is warning that he could vote against the $3.5 trillion budget package if more money isn’t added for housing assistance to close the racial wealth gap in the current House version of the bill, Axios has learned.

Why it matters: Warner’s threat is another indication that the proposal will face a variety of obstacles before the House and Senate can agree to a top-line number, how that money is spent on specific programs — and how to pay for it all.

• "As currently written, this proposal falls short,” Warner said in a statement to Axios about the House provisions on housing assistance.
• Warner, a member of the Budget Committee who helped negotiate the $3.5 trillion number in the Senate, is taking issue with the amount of funding for first-time homebuyers in the House, which he thinks is around $600 million.
• “I will be working in the Senate to make the American dream of homeownership and wealth creation more accessible to historically disadvantaged communities.”

The big picture: House and Senate committees are drafting specific legislation to raise $1.5 trillion in new revenues and spend some $3.5 trillion to expand the social safety net, including a variety of new programs from universal preschool to free community college to new money for housing and rental assistance.

• The top line numbers could dramatically change, with Sen. Joe Manchin (D-W.Va.) telling CNN’s Dana Bash that the $3.5 trillion package will “not have my vote.”
• Sen. Bernie Sanders (I-Vt.) also told the same program that Manchin's refusal to support the $3.5 trillion plan was "absolutely not acceptable to me."
• "I don't think it's acceptable to the president, for the American people, or the overwhelming majority of the people in the Democratic caucus,” he added.

Between the lines: Warner had negotiated a private agreement in the Senate for billions of dollars for down payment assistance for first-time homebuyers and to give them new tools — including a 20-year federal mortgage — to help them build equity in their home.

• Warner's focus is on racial equity: “We have an obligation to use this historic investment to address longstanding inequities of power and opportunity that have left Black families with an average net worth one-10th the size of their white counterparts."

Go deeper: Manchin has privately warned the White House and congressional leaders that he has specific policy concerns with President Biden's $3.5 trillion social spending dream — and he'll support as little as $1 trillion of it.