Just after the 1994 Republican Revolution, Christine Todd Whitman and other RINOs established the Republican Leadership Council. Their goal was to take the Republican Party back from the conservatives.
One thing they did was to establish open primaries so that conservatives would have less voting power and thus there would be more RINO primary winners. The RLC has done their job well.
Part of the RLC mission statement:
RLC-PACs vision is a Republican Party that is unified by the basic tenets of fiscal responsibility and personal freedom, but that allows for diverse opinions on social issues by its members.
RLC affiliates:
Alliance of Black Republicans
GreenGOP.org
Log Cabin Republicans
Main Street Coalition
National Republican Senatorial Committee
New America Foundation
The Piscataway Republican Organization
Planned Parenthood Republicans for Choice
Republicans for Choice
Republican Governors Association
Republicans for Environmental Protection
Republican Majority for Choice
The Whitman Series
The WISH List
There are a lot of divisions in that list.