Fact check: Why did the republicans say that Biden was declining cognitive

1. Summary of the results

Based on the analyses, Republicans made claims about Biden's cognitive decline through multiple channels and timeframes. The most recent developments show that Senate Republicans held hearings in June 2025 to investigate Biden's mental fitness, with Senate Judiciary Chairman Chuck Grassley framing it as examining "competency, corruption and cover up within the Biden administration" ^[1]. Senator John Cornyn stated their aim to "shine a light on exactly what went on in the White House during Biden's presidency" ^[2].

The Republican claims were based on several sources of information:

• A book by political reporters that alleged cognitive decline and staff cover-up, though the book had not been fully released at the time ^[3]
• A Wall Street Journal story claiming Biden showed "signs of slipping" behind closed doors ^[4]
• Various incidents throughout Biden's presidency that raised questions about his cognitive fitness ^[5]

President Trump specifically ordered an investigation into the alleged cover-up of Biden's decline, citing Biden's use of an autopen as evidence of his incapacity to execute presidential decisions ^[6]. Some Republicans even called for former First Lady Jill Biden to testify before Congress about the alleged "cover-up" of Biden's health ^[7].

2. Missing context/alternative viewpoints

The original question lacks several important contextual elements revealed in the analyses:

• The White House denied the allegations contained in the book that formed part of the Republican claims ^[3]
• The Wall Street Journal story faced significant criticism for its methodology and potential bias, as it "relied heavily on Republican sources" ^[4]
• Biden's team and supporters consistently pushed back against age and health concerns, arguing that he remained capable of performing his presidential duties ^[5]
• Democrats boycotted the Republican hearings on Biden's mental fitness, suggesting they viewed the proceedings as partisan rather than legitimate oversight ^[2]

Political motivations are evident: Republicans, particularly those supporting Trump, would benefit from establishing a narrative that Biden was unfit for office, as this could justify Trump's return to power and delegitimize Biden's presidency. Conversely, Democrats and Biden supporters had clear incentives to dismiss or downplay any concerns about cognitive decline.

3. Potential misinformation/bias in the original statement

The original question contains an implicit assumption that may reflect bias: it presupposes that Republicans' claims about Biden's cognitive decline were factual by asking "why" they made these claims rather than "whether" the claims were substantiated.

Key concerns about the Republican narrative include:

• The Wall Street Journal story that supported Republican claims was criticized for relying heavily on partisan Republican sources ^[4]
• The book cited as evidence had not been fully released, making independent verification difficult ^[3]
• The timing of these investigations and hearings, occurring after Biden left office, suggests potential political motivation rather than genuine oversight concerns

The framing of the question itself may perpetuate a one-sided narrative by not acknowledging the disputed nature of the cognitive decline claims or the strong denials from the White House and Biden's supporters.