The New York Times reports:

The group, the Conservative Victory Project, is intended to counter other organizations that have helped defeat establishment Republican candidates over the last two election cycles. It is the most robust attempt yet by Republicans to impose a new sense of discipline on the party, particularly in primary races.

…The Conservative Victory Project, which is backed by Karl Rove and his allies who built American Crossroads into the largest Republican super PAC of the 2012 election cycle, will start by intensely vetting prospective contenders for Congressional races to try to weed out candidates who are seen as too flawed to win general elections.