Yes, there have been proposals here and there over the years to abolish stepped-up basis, the most recent was in President Biden's FY22 proposed budget.
You may recall in the last year there has been some talk about taxing unrealized gains. While I oppose that idea and think it would be burdensome to administer especially for assets that are not regularly traded, that burden goes away at death in that one needs to obtain valuations to document stepped up basis... so it is more practical to do it then.
Additionally,
- President Biden's FY 2022 budget proposal sought to eliminate stepped-up basis and tax capital gains at death, with exemptions for certain assets
- The Sensible Taxation and Equity Promotion (STEP) Act, introduced by Senator Chris Van Hollen and colleagues in March 2021, aimed to close the stepped-up basis loophole by taxing unrealized capital gains when heirs inherit large fortunes
- In 2010, the bipartisan Simpson-Bowles National Commission on Fiscal Responsibility and Reform proposed taxing capital gains before investments were passed on to heirs as part of a comprehensive tax reform
- The Bipartisan Policy Center's Debt Reduction Task Force, led by Alice Rivlin and Senator Pete Domenici, included a similar proposal to reform stepped-up basis