Independently re-verified. All three cited sources are real, live, and support the outcome. (1) The Whitehouse Senate press release (whitehouse.senate.gov, Mar 13 2024) is genuine and confirms a refundable credit 'worth up to 10 percent of a home's purchase price - up to a maximum of $15,000' for first-time homebuyers, the amount Biden promised in 2020. (2) CBS News confirms Biden 'proposed a new tax credit that would provide $10,000 to first-time home buyers' in his 2024 State of the Union. (3) Multiple sources (The Mortgage Reports, congress.gov H.R.2863) confirm the First-Time Homebuyer Act was introduced by allied Democrats (Blumenauer/Whitehouse/Heinrich/Panetta), never advanced past committee, and was not enacted through the end of Biden's term. Biden's conduct exceeds a single supporting vote: he made the credit a 2020 campaign centerpiece, his administration backed the $15,000 First-Time Homebuyer Act, he included a homebuyer tax credit as a line item in his FY2025 budget, and he dedicated his March 2024 SOTU to demanding Congress pass it. That is active, sustained executive leadership of the effort that did not land -> CHAMPIONED, not ATTEMPTED (more than a single advance) and not PARTIAL/FULL (nothing was ever enacted; no credit exists). Confidence held at 0.7 rather than higher because Biden's own concrete presidential proposal downgraded the promised $15,000 to a $10,000 credit ($5,000/year for two years), a real erosion of the specific promise, and the effort ultimately failed to pass. This label would be applied identically to an opposite-party president with the same record of high-profile budget-and-SOTU advocacy for a reduced version that never became law.