Europe

What credibility was he losing when he called for a tactical vote which favors him the most? If the vote is only between Macron and Le Pen and the poll were so close you could not risk to not vote, it is obviously better for Mélenchon to call to vote for Macron and therefor against Le Pen.

Its a pure tactical move and I think also a more practicle solution to have Macron as president as opposed to Le Pen for Mélenchon but especially for NUPES

Yeah, calling to vote for Macron was pure opportunism. What I find encouraging is that the left is building dual power in France where they have serious political presence that's coupled with direct action such as strikes and protests. If this movement grows then it could lead to real systemic change.