Donald Trump has seen a number of campaign victories in recent days, including an endorsement from the New Jersey governor Chris Christie.
Mr Christie, who up until the Republican vote in New Hampshire was running against Mr Trump, now believes him to be "the best person to beat Hillary Clinton in November".
That has been enough to send Twitter into overdrive and soon the hashtag #NeverTrump was trending with users, regardless of thier political leanings, sharing reasons why they don't want to see Mr Trump win the Republican nomination.
Perhaps unsurprisingly, even Florida senator Marco Rubio, a Trump rival, got in on the act:
Some of those tweeting took issue with Mr Trump's attitude towards women:
#NeverTrump because my dad taught me to respect women, not belittle and demean them— Jacob Phillips (@lawrence15) February 27, 2016
Others were concerned about how Mr Trump feels about the disabled:
#NeverTrump because I do not want a Commander-in-chief that mocks the handicapped!— IowaCruzGirl (@iowacruzgirl) February 27, 2016
That's something that goes back to Mr Trump's mocking of New York Times reporter Serge Kovaleski who has arthrogryposis.
Some voiced concerns over Mr Trump's plans for a wall dividing the US and Mexico:
#NeverTrump because I believe we should be tearing down walls, not making others build them for us.— Ryan Ebert (@RyanEbertIs) February 27, 2016
Some expressed fears that he was unstatesmanlike:
Because the man thinks he can (a) bring no specifics & (b) insult everyone in the room, and then leave a negotiation having won. #NeverTrump— Will Antonin (@Will_Antonin) February 27, 2016
Other raised the issue of Mr Trump's supposedly stubby fingers, strangely something that appears to have plagued the candidate for quite a while:
#NeverTrump Because no nation has ever survived a leader with both narcissistic personality disorder and stubby fingers.— Brad Thor (@BradThor) February 27, 2016
And then there were those who worried what it might mean for them if Mr Trump actually becomes president:
Because I don't wanna have to move to Australia for 4 years #NeverTrump— Ben Platt (@BenSPLATT) February 27, 2016
Meanwhile, shortly after the trend began, supporters of Mr Trump started their own hastag, #AlwaysTrump.Reuse content