These marches are mostly rallies.  Most of the marching is getting to the rally point.  While there was an organic beginning to the events, most of the speakers were from established orgaizations. I suspect many of the supporters were already linked into to them as well.  This was mostly about rights, not democracy, and mostly reproductive, racial and gay rights, particlulary lesbians. I did not watch every speech, but it was not about globalization. Anti-globalization is what you find at Trump rallies.  These groups are coalition already, mostly through the Democratic Party. The question is whether this coalition can win back Congress in 2018.