Obama floated a single-payer option for healthcare, he was stopped by Republicans. People also need to realize that the Democrats scraping by means they have to compromise to survive.
You want them to do more? They need a mandate, not a razor thin slice. The Republicans have gerrymandered the fuck out of your country and made it so that even when they aren’t elected, they can control or block everything. They’ve made it impossible for Democrats to get a landslide, blocked absolutely everything they can, stirred up as much voter apathy as possible, so that even when they lose, they win. And you’re buying right into it.
This is also why everyone should vote Democrat. You only have two parties in your country. If the Democrats always win because the Republicans are too right wing, they will forced to abandon their most repugnant social policies to save the golden goose, tax cuts and cutting social programs.
This will force Democrats to move left to differentiate themselves, and so forth. Short of electoral reform which will never happen, it has to become political suicide to be against abortion, LGBTQ issues, etc like it is in other countries.