Not true. There are different churches that are called the Presbyterian church, just like the Lutheran named churches have conservative groups. They cannot be, nor should they be, lumped together.
PCA is the denomination associated with the Covenant School and is the largest conservative Calvinist denomination in the USA.
There are 40, or more, DIFFERENT Presbyterian church branches in North America according to Wikipedia.
Another protestant church that is undergoing schism is the First United Methodist Church which is following the liberal trend of accepting “married” homosexuals and lesbians as pastors among other liberal opinions. Conservative congregations are splitting off to either be independent or to join the Global Methodist Church.