Two factors generated that mythical age of Aquarius.
1. There were liberal Republicans and conservative Democrats, so parties were not as ideological as they are today, so it was more possible to peel off members of the other party for a particular policy than it is today.
2. For decades, whenever progressives proposed policies that were further and further from the enumerated powers of the Constitution, there was nobody (or almost nobody) in DC that would suggest, "Hang on a bit. What enumerated power is this policy pursuant to?" Whatever the president or Congress proposed was seen as ipso facto constitutional. In terms of limiting the Federal government to its enumerated powers, there was almost no opposition within DC. There is now. And progressives hate it.
But, yeah, I can see how you would pine for the time when progressives would slap a "kick me" sign on the backs of conservatives, and the conservatives would yuck it up with their opponents, laugh at their own misfortune, and meet their "pals" for a round of golf and a drink.
That was $19 trillion ago.