Republicans are on the cusp this week of passing a historic overhaul of the U.S. tax system but might also be ushering in a new period of instability in the tax code, because the plan is advancing without bipartisan support and with expiration dates that guarantee it will be revisited for years... One-time revenue sources like a $339 billion tax on stockpiled foreign profits pay for long-running tax cuts, making the bill more costly in the future. Key features—including the $2,000 child tax credit and a $10,000 cap on the state and local deduction—aren’t indexed to inflation, eroding their real value over time... “It’s just the beginning. It’s a whole new chapter,” he said. “It’s built on unstable financial foundations and on unstable political foundations. And it was built in great haste.”.. “In the short term, the bills are unpopular because the losers scream the loudest,” said Brian Riedl, a senior fellow at the free-market-focused Manhattan Institute. “And in the long term, they are hard to repeal because the beneficiaries are the loudest.”
.. But other pieces—a doubled estate-tax exemption, a new tax break for pass-through business owners, the 21% corporate tax rate, limits on the state and local tax deduction for individuals—are ripe to be reversed or scaled back.A future Democratic Congress and president could also dial up tax rates on high-income households and businesses.