WASHINGTON—The Trump administration is scaling back tax enforcement, leaving fewer federal employees to audit returns, collect unpaid tax debts and deter Americans from skirting the law. The Internal Revenue Service has shed thousands of enforcement workers since President Trump returned to office, and his fiscal 2027 budget proposal seeks further cuts amid the administration’s broader pullback of white-collar law enforcement. The IRS enforcement workforce would fall below 30,000, fewer than at the end of Trump’s first term and about a third less than the Biden-era peak . The retrenchment is spurring a vibe shift across the tax landscape ahead of…