Oh right, I forgot about gay marriage - that issue has been lost for Republicans already, but Trump also supported gay civil unions, an expansion of the Civil Rights Act to include a prohibition against discrimination against gays, and for gay people to be allowed to serve openly in the military.
Donald Trump's Big Gay Problem | Mother Jones
Seriously, almost any political or social issue, if you look it up, Trump used to be liberal before he decided to run for president. A record like that would bury any other Republican candidate.