@revelette1,
Couple things.
1) we will likely only get the majority by backing some of these moderates. If you don’t back them or they don’t win then there is no majority and you don’t get to have this discussion go any further.
2) there were moderates when Obamacare was passed. That was a hugely positive step in the right direction even though no one got everything they wanted.
3) Dodd-Frank was also passed with moderates in the Democratic Party.
4) There will never be 60 Bernie Sanders-types elected. Compromise is a must in government.
5) You also have to understand that even if candidate X was against abortion, if the majority of the party is pro-choice then candidate X will never even get the chance to cast a vote on any abortion related bill. The majority party sets the legislative agenda. Minority viewpoints within a party barely get any airtime. Just ask Rand Paul.