Sinema doesn't want to tighten carried interest from the Manchin bill.
She was known to object to the tax measure that helped wealthy investors.
Sinema hasn't commented on the bill yet.
There is a provision in the economic spending bill that benefits rich investors.
Sinema wants to kill a Democratic measure to narrow the carried interest tax loophole and add $5 billion to the package, according to reports.
A person for Sinema did not respond to a request. Senate Democrats cannot advance the package in the Senate without her support. Budget reconciliation is a tactic used by the party to pass a bill along party lines.
Both Republican and Democratic administrations have failed to eliminate carried interest for a decade. Hedge-fund managers get a percentage of profits from their investments.
That compensation is taxed at a lower capital gains rate that maxes out at 23.8%, unlike most Americans who pay a higher income tax rate. Critics say it's a big hole in the tax code.
Efforts to close the loophole were opposed by the Arizona Democrat. She is on a collision course with Sen. Joe Manchin.
Manchin supports the measure. He was a part of a bill that eliminated carried interest last year. He told reporters that he was adamant about the carried interest.
No one had spoken to Manchin about the reports that Sinema wanted Democrats to get out of the way.
Sinema hasn't commented on her views on the legislation yet. She told Morgan Rimmer that she was taking her time.
Business Insider has an article on it.