[jsperson]

I realize that your question is rhetorical, but I'm not sure the facts supports your point. Democrats controlled both the House and Senate from 2009-2011 and controlled the Senate all the way up through 2015. All the while controlling the Presidency as well.

[metabagel]

Practically speaking, you need 60 votes to control the Senate. Barring that, the opposition party has great power to block legislation.

[gurumeditations]

And yet Republicans controlled the White House, Senate, House, and the Courts from 2016-2018 and only managed to pass a $1 trillion taxpayer-funded giveaway to the largest corporations and a few rule changes to make it easier to dump toxic waste into drinking water.