In order to do that, they're going to need to start making some serious changes:
1. Become the party of free speech. What is happening on college campuses is not something I will ever support. No safe spaces, no shouting down someone who doesnt define racism as "prejudice plus power". The regressive left is killing your party.
2. Stop supporting foreign policies that are as bad as the neocons. We don't need to export democracy to Libya, Syria, Yemen, Egypt... We don't need to engage ourselves in civil wars in other countries. We are not the world police. Follow the money for this election and it is painfully obvious that HRC was the candidate for the military industrial complex as much as she was for transgender bathrooms.
3. Stop pushing for foreign trade deals that further depress domestic wages. HRC stopped supporting TPP because Bernie and Trump were against it. If we get wage growth, entitlement expansion isn't necessary to capture the electorate and left candidates will be able to advance all the LGBT social reforms they want without scaring the moderate right away with tax increases.
HRC won the popular vote this time, but a lot of the GOP turnout effort was half assed because they never thought Trump would pull it off. Reorient the party towards blue collar, or keep doing the same old same old and lose. This election cost you the Supreme Court. You really don't have any choice other than to move to the middle.