The Cubans from Florida (click here). I am fairly sure that is why Rubio was re-elected.
The Democrats need to continue to influence change within the states of Florida and Texas while they shore up California. The Blue Wall needs to be reinforced otherwise this new populous trend will continue to hack away at Democratic support.
The Millennials voted for non-traditional candidates. That will continue. The DNC has the best adviser for the future in the Independent from Vermont. I strongly suggest they heed his words.
The fund raising among the electorate needs to continue post election and into the elections of 2018 and beyond. The DNC has a very different political paradigm to deal with and the Sanders constituent may be in the process of starting a new base of success in those voting outside the traditional parties. The DNC can either adapt or continue to loss their representatives in the US House and US Senate.