“Zero federal income tax” sounds simple until the mechanics show up. Booker’s bill would get there by expanding the standard deduction from $16,150 to $37,500 for single filers, $24,200 to $56,250 for heads of household, and $32,300 to $75,000 for married couples filing jointly, according to PWBM in March. Taxpayers with income below that amount owe nothing in federal income taxes, PWBM explained earlier this month.

Van Hollen’s bill works differently. Eligible filers would calculate their liability under the normal rate schedule and under an alternative formula equal to 25.5% of adjusted gross income above a cost-of-living exemption, then pay whichever is lower, per PWBM in March. Filers below that exemption owe zero, and eligibility stops cold once AGI rises above 175% of the exemption amount.

Bezos enters the story because his own tax profile is a tidy illustration of the system’s blind spots. ITEP said his net worth rose by $99 billion from 2014 through 2018 as his stock climbed, while his income as defined by the tax code was $4.2 billion, according to ITEP in April 2024. Economists may treat that unrealized appreciation as income, but current tax rules do not, so it is not taxed as ordinary income unless realized, ITEP said. That is the contrast this debate keeps bumping into: wages can be shielded more generously, while asset growth stays in the background.

The price tags are nowhere near each other. KYPA’s standard deduction expansion would reduce federal revenue by an estimated $5.1 trillion over fiscal years 2026 through 2035. WATCA’s rate-cap approach would cost about $1.4 trillion over the same period, per PWBM in March.

That gap is built into the design. Each extra dollar of standard deduction is worth more to filers in higher brackets, because it shields income that would otherwise face a higher marginal rate, PWBM said. A rate cap does not work that way. It limits the tax bill directly, so the cost stays more contained.

The full KYPA package is even larger. Because it also expands and makes fully refundable the Child Tax Credit and broadens the Earned Income Tax Credit for childless workers, PWBM estimated the bill would reduce federal revenue by $6.4 trillion over the ten-year budget window beginning in 2026, according to PWBM earlier this month. Booker has said the lost revenue would be offset by raising the corporate tax rate, strengthening corporate tax rules, increasing taxes on stock buybacks, tightening limits on executive compensation deductions, and other measures, but has not provided details, PWBM reported.

The politics sound like a middle-class tax cut. The distribution does not always cooperate.

Under KYPA’s deduction expansion, benefits rise in dollar terms as income rises. Households in the second quintile would average a $445 tax cut; the middle quintile would average $2,065; the fourth quintile $4,705; and households in the 80th to 90th percentile $7,165, per PWBM in March. Even the top end keeps collecting meaningful gains: the 99th to 99.9th percentile would average $6,445, and the top 0.1% would average $6,265.

That is the uncomfortable part for anyone selling the plan as relief mainly for lower earners. The biggest checks do not stop at the middle of the income scale; they keep rolling upward.

WATCA looks more tightly aimed at the center. PWBM found that the middle and fourth quintiles would receive the largest average cuts, $1,505 and $1,545 respectively, while benefits above the 80th percentile drop to zero because the eligibility cap excludes those filers, per PWBM in March. In other words, the Van Hollen version has a hard ceiling. The Booker version does not.

The broader KYPA package follows the same pattern. Households earning $100,000 to $200,000 receive the largest tax cuts in dollar terms, while the lowest-income quintile sees the largest percentage increase in after-tax income, according to PWBM earlier this month. That distinction is not a footnote. It is the whole argument over whether these proposals are aimed at workers near the bottom or households farther up the ladder.

A bigger standard deduction sounds clean. The code underneath gets messier.

If KYPA became law, the share of filers choosing to itemize would fall from 13.3% under current law to 2.3%, a reduction of about 18.5 million filers, per PWBM in March. That would leave only a sliver of taxpayers still able to benefit from itemized deductions.

The practical effect is blunt. Charitable giving and mortgage interest deductions only matter if a filer itemizes, so those incentives would effectively disappear for most households. At 2.3% itemization, they survive mainly for the highest earners with the biggest deductible expenses.

WATCA creates its own problem, just a different one. Because eligibility cuts off at 175% of the exemption amount, a filer just above the line gets nothing while a filer just below it gets relief, per PWBM in March. That kind of cliff can encourage awkward behavior near the boundary. Tax policy has a way of rewarding people who can count in cents.

Both proposals would widen the zero-tax zone. They would not do it in the same way, they would not cost the same, and they would not help the same people.

WATCA is the more targeted plan, with a $1.4 trillion price tag over a decade and benefits concentrated in the middle of the income distribution, per PWBM in March. KYPA is much more expensive at $5.1 trillion for the deduction expansion alone, and its largest dollar benefits tilt toward upper-middle and high-income households.

Booker still has not produced a detailed financing package for KYPA’s broader $6.4 trillion cost, PWBM said earlier this month. Until lawmakers explain how they would pay for these cuts, the debate stays where it began, in the comfortable zone of rhetoric and the uncomfortable zone of arithmetic.