The Democrats and Republicans may be worlds apart on most things, but at their headquarters just two blocks away from each other on Capitol Hill, each is confronting the same question: Have political parties lost their purpose?

In the wake of two presidential defeats, the Republican National Committee on March 18 unveiled what it is calling its Growth and Opportunity Project, which is an effort to take the existing party engine and give it a top-to-bottom tuneup.

"There's no one reason we lost. Our message was weak; our ground game was insufficient; we weren't inclusive; we were behind in both data and digital; and our primary and debate process needed improvement," RNC Chairman Reince Priebus said the same day. "So, there's no one solution. There's a long list of them."