Part 2
Simply put, all of this can be reduced to taking the heartfelt desire Jesus expressed the night before he was killed that We all might be one.

The "ecumenism" that all ecumenists (not just liberals) are against is the alliance of (1) a sub-set of Catholics (various labeled traditionalist, conservatives) who are generally four square against ecumenism as just defined, clinging instead to the former demand all other Christians simply convert to Catholicism, and (2) American Christian fundamentalists, based on a shared xenophobia and Islamophobia, with a shared enemy that includes fellow Catholics (despised as liberal, progressives) and liberal secular values.

It is, ultimately, an alliance of hatred focused on differences; and as such contrasts in every conceivable way from the V2 ecumenism of shared commonalities and mutual respect.

Thus the irony that the one word "ecumenism" is proffered for diametrically opposite attitudes. 

Sure hope that helps, Jay. Not difficult really.