Why Does the Republican Party Exist?

 Is it just an arbitrary entity seeking a universal negative, designed to push back against Democratic policies and demand they be more something (efficient) or less something else (expensive)? Or does it have actual principles and priorities it seeks to make a reality? 

The Republican Party’s voters and supporters certainly seem to have such beliefs. But they rarely seem to make it through the process of synthesis that turns such beliefs into actual policy priorities. Being a negative force is not nothing, and blocking bad policy is worthwhile. But when given the opportunity to put good policy into place, or to take steps to make such policy more feasible in the future, where is the Republican Party to be found?

So why does the Republican Party exist?  This article does give an answer or two.  They're not good answers.  But they look pretty accurate to me.