The First 100 Days of a John Thune Presidency: What the Record Suggests

Hero photo: Cornerstone, South Dakota State Capitol, Capitol Avenue, Pierre, SD — File:Cornerstone, South Dakota State Capitol, Capitol Avenue, Pierre, SD.jpg, via Wikimedia Commons.

01 The scenario

John Thune of South Dakota is the Senate Majority Leader — elected by the Republican conference in November 2024 after succeeding Mitch McConnell — and a senator since 2005. This article asks a hypothetical question: if he were ever sworn in as president, what would the first 100 days look like based on his documented record? This is a scenario analysis, not a prediction that the person will become president and not an endorsement or criticism of the person.

The premise rests on a specific record: steering the One Big Beautiful Bill Act through a 51-50 Senate, four farm bills, a career-long broadband and telecom portfolio, estate-tax opposition “in any form,” and an institutionalist leadership style. A reasonable inference from these positions is that a Thune White House would be a legislative-presidency scenario — the digest notes his leverage is legislative, not unilateral, and a new president's first 100 days would hinge on the same floor-control skills he now owns. The pieces a president could do alone are modest: E15 by EPA action, permitting streamlining, and SNAP administrative rules.

02 The record: who John Thune is

Thune is a Republican and South Dakota's senior senator, in the Senate since 2005; he defeated Senate Democratic leader Tom Daschle in 2004 after serving in the U.S. House from 1997 to 2003. He was elected Majority Leader by the Republican conference in November 2024, defeating Sen. John Cornyn 29-24 after Rick Scott was eliminated. He was previously GOP Conference chair (2012) and Whip (2019).

Born in Pierre, South Dakota in 1961, he was a legislative aide to Sen. Jim Abdnor, a Reagan-era Small Business Administration appointee, and director of the South Dakota GOP, the state Railroad Division and the Municipal League. His committees: Agriculture, Nutrition & Forestry (longtime member, helped craft four farm bills); Finance; formerly chaired Commerce, Science & Transportation; and ranking Republican on the Communications, Media & Broadband Subcommittee.

03 Tax policy and the OBBBA

Thune's defining 2025 achievement as Majority Leader was passage of the One Big Beautiful Bill Act (H.R. 1), signed July 4, 2025 — passed 51-50 in the Senate with Vice President Vance's tiebreaker (final House vote 218-214). He held GOP losses to three (Collins and Tillis over Medicaid, Paul over the debt ceiling) and personally negotiated Sen. Murkowski's decisive vote. He admitted afterward there were times “I wasn't sure I could get it to Trump's desk.”

In his June 22, 2026 floor speech on the “Working Families Tax Cuts,” he said Republicans “set out to prevent that tax hike” of $4 trillion, citing the senior deduction (35M seniors), no-tax-on-tips (7.5M workers), the overtime deduction (29M workers), the permanent R&D credit, and 100% immediate expensing for equipment.

The lever is unambiguous: tax law requires Congress by definition. This would require congressional approval rather than unilateral presidential action — which is precisely the machinery Thune has proven he can operate.

04 Agriculture and the farm bill

A longtime Ag Committee member who helped craft four farm bills, in September 2026 Thune pushed the Senate farm bill out of committee on party lines — Democrats objected over SNAP state cost-share timing. He said the parties “always seem to come together at the end” and accused Democrats of “block voting” against a bill “principally about production agriculture.”

He supports year-round nationwide E15 ethanol sales — and here the digest finds a unilateral lever: EPA waiver action, which Congress also pursued. His prior bills include the American Beef Labeling Act (mandatory country-of-origin labeling for beef via WTO-compliant means) and the Promoting Precision Agriculture Act.

SNAP administrative rules could shift by executive action, the digest notes, though the statutory cost-share changes need Congress.

05 Rural broadband and telecom

Broadband is a career signature: the former Commerce chairman authored the Small Business Broadband Deployment Act (S. 2283, reported 2016) and the Accelerating Broadband Permits Act of 2026 (S. 4448, introduced April 30, 2026; ordered reported by Commerce July 22, 2026). His broadband-streamlining provisions target areas where at least 90% of households lack broadband.

The permitting-process reform is the one piece the digest flags as executive-branch executable — a president could streamline permitting in-branch while S. 4448's codification went to the Hill.

06 The estate tax

Thune is a long opponent of the estate (“death”) tax “in any form,” including as a Finance Committee member fighting Democrats' proposed changes — the position is documented in his own op-ed, “Sticking Up For South Dakotans.”

Estate-tax repeal is a statute. In a first-100-days scenario this is a priority a president could only advance through the congressional lever — and one where Thune's Finance seat and leader role would matter more than the presidency's unilateral tools.

07 The institutionalist: floor control as the presidency's first constraint

Thune's own statements emphasize Senate institutionalism, and his majority-leadership role makes him the gatekeeper of what reaches the floor. The digest draws the scenario-relevant conclusion directly: for a new president's first 100 days, his cooperation — or obstruction — determines whether reconciliation, nominations, and Congressional Review Act measures advance.

A reasonable inference from these positions is that a Thune presidency would treat Congress as the primary instrument — his record contains almost no unilateral-executive agenda beyond the E15, permitting and SNAP administrative items.

08 What the record cannot tell us

The evidence runs out in specific places. There is not enough public evidence to determine Thune's personal positions on tech/AI and foreign policy — the digest states his leadership role subsumes much issue advocacy and no position should be assumed. Floor-management details beyond the OBBBA vote counts were not captured, and his 2028 re-election status (Ballotpedia lists him as running) should be treated as early rather than an active race.

One structural caveat: nearly everything documented about Thune is about how he moves legislation — not how he would use executive power. The record describes a master of the congressional lever; it says very little about his instincts on executive orders, emergency powers, or agency direction beyond the three unilateral items the digest identifies.

Disclaimer: this article is a scenario analysis based on the documented public record as of September 21, 2026. It is not a prediction that John Thune will become president, nor an endorsement or criticism of him or his positions. Where evidence is incomplete, that is stated rather than filled in.