Individual politicians and political parties routinely use count a vote as approval. In that way, if no other, voting does serve to support the existing system.
I don’t think that tracks.
The highest turnout in any US election since 1908 was 62% in 2020, and at no point has a party won an election and been like ‘look at all the people who didn’t vote, I guess we don’t have a mandate to govern’
Parties win elections and govern in power with less than 50% of voters backing them all the time, it’s literally the standard. A low turnout will not change the way any party acts once in power.
Yes I mean, he’s not wrong but his thing about Ukraine is driven by his Churchill obsession, not by real world ethics