I think you misunderstand the libertarian position. You can lobby a minimalist government all you like, it can't do anything to help you because it doesn't have the power or resources to do so.
The thing I find silly with libertarianism is that you're describing an ideal with a massive power vacuum - one that will be filled. So government is minimalist and ineffectual, in that case, they are a sham and the real "governance" is done by large corporations/wealthy behind closed doors.
Similar downsides as a large central government, but you have no vote unless you're massively wealthy/powerful.
By 'constraining and defunding the government' I basically mean smaller government in budget & scope/mandate. Is that different from your definition of minimalist?
Similar downsides as a large central government, but you have no vote unless you're massively wealthy/powerful.