"Declining" Influence in Latin America

I've constantly been lamenting the lack of evidence for the "U.S. is losing Latin America" meme (such as here). One of the very interesting things about this argument is how it brings the left and the right together in agreement, but with different assessments about whether it is positive or negative.

There is an example today in The Week. The author starts with an assumption:

The decline of American influence in Latin America is long overdue and great news to boot, for two major reasons.

He then cites the historically negative effects of U.S. policy, and how that spawned authoritarianism, going back to the colonial period. Nowhere, though, is there an examination of precisely how influence is declining or why. He concludes with something I agree with completely:

Evo Morales may well try to hang on to power indefinitely — it wouldn't be the first time a populist leader has done so. But there's little the U.S. can do about that but make it worse. It's time we left Latin America to manage its own internal politics.

Absolutely! But there is no evidence presented for the influence decline--it is assumed. Whether or not Evo Morales is re-elected isn't necessarily an example, as plenty of presidents the U.S. doesn't like have done so over the past century or so.