They are probably referring to a study suggesting that Black and Hispanic families are more often suffering from non- or underpayment of child support (and from lesser amounts of support being ordered) than among White families [1]. That together with voter demographics going strongly for Democrat support among Black families [2] makes this at least a correlation supported by facts.

However, I think it is not causal because under- or nonpayment of child support is linked to financial difficulties and income disparities, which non-White people are experiencing at significantly higher rates.

[1] https://www.irp.wisc.edu/wp/wp-content/uploads/2024/01/CSRA-...

[2] https://www.pewresearch.org/politics/2024/04/09/partisanship...