In her view, a man who could not safeguard an election outcome while commanding the full powers of the presidency has even less capacity to determine who becomes President now that he is a private citizen.
She made specific reference to Uhuru's reported backing of former Interior Cabinet Secretary Fred Matiang'i, suggesting that such support carries little weight given what she described as his failure to deliver for Raila when it mattered most.
The argument cuts to a debate that has been simmering within Kenyan political circles since the 2022 election.
Raila Odinga lost that contest to William Ruto in a result that was upheld by the Supreme Court, but questions about whether Uhuru did enough to support his preferred candidate have never fully gone away. For Mboko, the answer is clear, and she is saying it publicly.
Having taken aim at Uhuru, the Likoni MP turned her attention to Gachagua, who was impeached as Deputy President and has since been building a political vehicle of his own under the DCP party banner.
Mboko questioned the foundation of his ambitions, pointing to what she described as his failure to mobilise sufficient support in both the Senate and the National Assembly to halt his own impeachment.
Her argument is direct. A leader who could not rally lawmakers to defend his own position, she suggested, is not credibly placed to unite or influence a country of more than 50 million people.
The impeachment, which succeeded despite Gachagua's efforts to fight it, remains a raw wound in his political biography, and Mboko showed no hesitation in pressing on it.