The First 100 Days Matrix: What Nine Potential Presidents Could Change Without Congress

Hero photo: US Capitol west side — Martin Falbisoner, Wikimedia Commons, CC BY-SA 3.0.

01 The record and the matrix

This is the capstone of a 25-part series, and it starts where every installment started: scenario analysis, not a prediction or endorsement. As of September 18, 2026, AP describes Gavin Newsom and Kamala Harris as potential 2028 Democratic contenders and reports Republican discussion around JD Vance, Marco Rubio, Ron DeSantis and Ted Cruz; most figures profiled have not formally entered a presidential race. No one is predicted to win anything. The nine figures in this matrix — Vance, Rubio, DeSantis, Cruz, Newsom, Harris, Whitmer, Shapiro, Ocasio-Cortez — share exactly one thing: a verifiable record that implies a first-100-days agenda.

The matrix method is simple. Every proposal any of the nine has verifiably supported or implemented sorts into one of five authority classes: executive authority (orders, personnel, priorities, diplomacy — days, not months), regulatory action (agency rulemaking — starts in 100 days, finishes in 6-18 months), budget reconciliation (taxes and spending — 50 votes plus the vice president), ordinary legislation (everything else — 60 votes), and constitutional constraint (naturalization, declarations of war, appropriations — Congress alone, forever). The rows below are each figure's documented record; the bucket column is the law; and the pattern that emerges is the article.

02 Immigration — the matrix in miniature

Immigration is the clearest test of the method, because the nine records span the full authority spectrum while the constitutional floor sits in the same place for all of them. Only Congress naturalizes — the constraint Ocasio-Cortez's own 2021 letter to Senate leadership conceded while fighting the parliamentarian, and the one every citizenship-pathway proposal from Harris to Rubio collides with identically.

The pattern: Republicans (Vance, Rubio, DeSantis, Cruz) hold enforcement agendas that are largely executable — priorities, agreements, preemption — because enforcement power is the executive's most-court-deferred domain. Democrats hold reversal agendas that are partly executable (priorities, parole, TPS designations — the exact tools the 2026 Supreme Court rulings affirmed executive discretion over) and partly impossible (E-Verify repeal, decriminalization, citizenship — all bucket four and five). Cruz's mandatory E-Verify and Ocasio-Cortez's decriminalization bill are the same kind of object: a senator's wish list that only a Congress can grant. The first 100 days of any of the nine changes immigration enforcement almost immediately and immigration law not at all.

03 AI and technology — the fastest-moving square

AI is the youngest policy domain in the matrix and therefore the most executive-shaped: the federal AI state was largely built by executive order, procurement, and export controls, which means a president can redirect it by the same instruments. The nine records split less by party than by theory: regulate the technology (Newsom's transparency-and-kill-switch EO model), regulate the adversary (Rubio's export-control model, DeSantis's procurement bans), industrialize it (Vance's diffusion-and-defense model, Shapiro's data-center siting model, Whitmer's workforce model), or slow it (Ocasio-Cortez's moratorium bill).

Notice the bucket distribution: export controls and procurement are agency actions — bucket two, available to all nine within days. The Sanders-Ocasio-Cortez data-center moratorium is bucket four, a statute. And the compute-subsidy race (Vance, Shapiro, Whitmer all want it) is bucket three, reconciliation, which means it happens if and only if the Senate calendar allows — the single most underappreciated variable in every tech agenda in Washington.

04 Taxes and energy — where the 50-vote machine lives

Taxes and energy are where the matrix gets mechanical, because both domains are reconciliation-native: taxes are the paradigmatic reconciliation subject, and energy policy is mostly tax credits and fees wearing costumes. Cruz's Natural Gas Tax Repeal Act, Vance's tariff program, Harris's child-credit expansion, Shapiro's rebate model, DeSantis's tax cuts, Ocasio-Cortez's rate restoration, Rubio's industrial credits, Whitmer's working-family credit — all bucket three. In any given first 100 days, one or two of them are achievable, and which ones depends on nothing but the Senate math and the calendar.

Energy adds a second pattern: both parties' agendas are executive-heavy at the top and statute-dependent at the core. DeSantis's rollback and Newsom's mandates are both executable as rules (bucket two) and both incomplete without statutes (bucket four) — the Florida HB 1645 model and the California SB 100 model only became durable because state legislatures passed them. A president either inherits a legislature or does not; the matrix says the governor-figures (all four) know this better than the rest.

05 Healthcare and education — the slow squares

Healthcare and education produce the matrix's most counterintuitive result: the biggest promises are the least executable, and the smallest are the fastest. Medicare for All — Ocasio-Cortez's signature — is bucket five wearing a bucket-four costume: even 50 Senate votes cannot create a national health program through reconciliation, because the Byrd Rule strips policy from budget, as every parliamentarian since 2025 has demonstrated. School choice — DeSantis's and Cruz's signature — is the same object in the other direction: education savings accounts and tax credits are ordinary legislation with a reconciliation side door for the credit mechanics. What executes fast in both domains is the unglamorous middle: waivers (Vance's Medicaid experiments), price-transparency rules (DeSantis, Shapiro — both have signed transparency instruments), loan-administration relief (Ocasio-Cortez's debt-relief litigation record), accreditation (Vance's university fight — a regulatory lever).

The first-100-days truth in both domains: spending increases (Harris's Title I, Whitmer's pre-K, Shapiro's adequacy funding) ride reconciliation and might pass; structural changes (M4A, national school choice, debt-free college) are 60-vote statutes that have never been closer in any of the nine's lifetimes.

06 Defense and regulation — the commander and the administrative state

Defense is the most lopsided square in the matrix: the commander-in-chief clause gives every one of the nine more unilateral authority in this square than any other. Vance's burden-shifting to Europe, DeSantis's Ukraine skepticism, Rubio's hemispheric realignment, Harris's NATO continuity — all executable as deployments, posture, and diplomacy within weeks, with Congress's real power (appropriations) arriving later. Ocasio-Cortez's DoD-skepticism is the sole exception that requires Congress — cuts ride reconciliation but the politics have never existed even in her own caucus, a fact her 2026 pivot (disavowing defunding DoD) quietly concedes.

Regulation is the mirror-image square: it is where the administrative state's plumbing gets rebuilt. Vance inherits a unitary-executive doctrine his own administration built; Cruz wants to codify deregulation so it survives him (his entire bill record is bucket-four lawmaking for exactly this reason); DeSantis wants REINS-style congressional veto; Newsom and Harris want rules restored; Shapiro wants deadlines and published metrics; Ocasio-Cortez wants agencies expanded — which, again, costs money (bucket three) or statute (bucket four). The nine-way pattern: Republicans regulate by deregulating; Democrats deregulate by regulating; and the administrative state changes hands faster than any of them can change it.

07 What the matrix says courts and Congress could constrain

Read across all eight policy squares, the matrix produces five findings that no individual profile could show alone.

One: every figure's Day 1 exists, and it is smaller than every figure's campaign. Buckets one and two — orders and rules — are available to all nine, and all nine would use them. The first 100 days of any of these presidencies is genuinely consequential and genuinely partial.

Two: every centerpiece is bucket four. Medicare for All, mandatory E-Verify, national school choice, a clean electricity standard, the Green New Deal, Cruz's Energy Freedom Act — 60 votes each, none closer than the last 20 years of Senate history. The 100-day window is a spotlight on the difference between what candidates promise and what presidents can sign.

Three: reconciliation is the real first-100-days legislature. Taxes, energy credits, spending — bucket three — is where each agenda's executable half lives, and the Senate calendar, not the president's pen, is the binding constraint. A first 100 days without a reconciliation vehicle is a first 100 days of press releases.

Four: the constitutional floor does not move. Naturalization stays with Congress no matter how many letters Ocasio-Cortez sends to the presiding officer; war powers stay with Congress no matter how far Vance shifts deployments; appropriations stay with Congress no matter what any of the nine proposes. The 2025-2026 Court constrained and empowered all nine figures simultaneously — expanding executive discretion in immigration and agency control while shrinking it for regulatory ambition — which means every one of these presidencies inherits the same double-edged doctrine.

Five: the matrix is not a prediction, and that is the point. It maps what nine verified records imply against a single authority structure that none of them can change in their first 100 days — or, for that matter, in any 100 days since the Byrd Rule, the filibuster, and Article I last moved. Whoever sits in the office in 2029 will face the same five buckets. The only open question is which bucket their voters were promised.