The #NeverTrump hashtag grew rapidly Friday evening, eliciting tweets from across the political spectrum to become the top trend on Twitter not only in the U.S., but worldwide.
Criticism of Trump touched on an array of topics, including his contentious relationship with the Latino community.
And the way he has campaigned for the GOP nomination.
Others questioned Trump's past financial activities.
Some echoed Marco Rubio's attacks Friday on Trump's spelling errors:
The hashtag included multiple references to Nazi Germany.
The hashtag rose to prominence just hours after former Mexican President Vicente Fox said Trump "reminds me of Hitler."