Both cited sources are reachable, both verbatim quotes are confirmed present, and both document the correct outcome for this specific promise. The PRIMARY source (Stitt's own governor's office) confirms he signed HB 4072 creating the $200M Oklahoma Taxpayer Endowment Trust Fund to advance the "path to zero income tax," with the pivotal-moment quote present verbatim. The REPUTABLE_SECONDARY source confirms he signed HB 2764 (May 29, 2025) cutting the top marginal rate from 4.75% to 4.5%, consolidating six brackets into three, and embedding a 0.25%-increment trigger mechanism toward full elimination — matching the promise (incremental cuts with the stated goal of full elimination). On the leadership test: the second source notes Stitt did not author/sponsor HB 2764 (legislators Caldwell and Hall wrote it), but a governor cannot constitutionally author or sponsor legislation — the executive leadership pathway is setting the agenda, driving priority, and enacting the bill. The same source affirmatively documents Stitt as having "championed" the concept via his "Half and a Path" plan and being "a driving force behind the initiative's priority status," and his own office frames the signings as the "path to zero." This is genuine executive leadership, not a mere vote or passive signature, so CHAMPIONED is upheld rather than downgraded to FULL.