IMO, what Thiel wrote is essentially that women and non-whites are beneficiaries of welfare and leaches on society, and that they therefore will vote to transfer wealth from the white men who create it (according to Thiel).
> The 1920s were the last decade in American history during which one could be genuinely optimistic about politics. Since 1920, the vast increase in welfare beneficiaries and the extension of the franchise to women — two constituencies that are notoriously tough for libertarians — have rendered the notion of “capitalist democracy” into an oxymoron.
https://www.cato-unbound.org/2009/04/13/peter-thiel/educatio...
> The 1920s were the last decade in American history during which one could be genuinely optimistic about politics. Since 1920, the vast increase in welfare beneficiaries and the extension of the franchise to women — two constituencies that are notoriously tough for libertarians — have rendered the notion of “capitalist democracy” into an oxymoron.
(edited to remove a redundant word)