Party unity in a "big tent" party
You cannot have party unity in a "big tent" party. If we are going to have a wide range of ideological perspectives in the GOP, then we have to expect there will be heated disagreements and debates about public policy. Sometimes, these debates will become bitter arguments.
It is not realistic to expect people who have wide differences on public policy will not criticize each other and sometimes refuse to support candidates who have wildly different perspectives on public policy.