It's really not. The violence from the alt right during this Neo Nazi demonstration is receiving condemnation from everyone, left, right, and center. Except, unsurprisingly, Donald Trump.
Far from showing the strength of the alt right movement, it's nothing but a big setback for them and their ideals. They are dangerous people and need to be taken seriously. But the ground is not crumbling, not by any means.
I want to believe this, but I'm skeptical. They don't have to be the majority, they just have to be the ones in control--and right now, they are. Yes, various GOP members came out with strong and clear statements against the white nationalists and their actions in VA, but thus far we've got nothing that shows us they will back up those words with their votes and actions. What was it, two weeks ago our current DOJ said gay rights weren't protected under Federal civil rights? We've basically got nazis in the White House advising the president and making statements to the press.
As for "regular people" who voted for 45 but say they don't support the white nationalists, what I saw/heard today was them still referring to the nazis at the rally as alt-right and lots of straw men arguments refusing to discuss what was actually happening, instead only focusing on the right to free speech. Maybe those willing to carry torches are only a few thousand or a hundred thousand nationwide, but those regular people unwilling to step up and say a clear, firm NO, willing to accept the loss of rights for fellow Americans and violence against them? Now we're talking about tens of millions.