When I first heard about the joke, I thought it was "meh" and didn't get it. Then I watched it and I totally got it. I think the idea of eating the sheet cake and yelling into the cake is a metaphor to the feeling of helplessness to what is going on since 45 has taken office--hell even during his campaign. With all the money donated to organizations like the ACLU, NAACP, Planned Parenthood, the Democratic Party, Hillary Clinton, et al, this donkey Trump still became president and started dismantling everything President Obama worked for. The writing the congressmen, the calling of senators, the NYT Op-Ed pieces, the late night talk show skewering, and Donald Trump and the racists and the homophobes and the woman haters seem to be getting more power, becoming more bolder, and we just seem to be losing. Individuals and groups are pushing back with all our strength and Trump seems to still be winning--calling news outlets fake, lying about Russian collusion, bringing us to the bring of WW3 with North Korea, and pulling us out the Paris Accord and denying climate change AND LGBTQ rights.
Besides a successful assassination attempt or moving my entire life to another country, what else I can I do to fight Trump and is supporters? If doing all the proper things doesn't seem to work, eating cake may be just as effective tool.
The joke could have been executed better but I think this was the general gist. I am not a ride or die Tina Fey fan but I don't think her heart was in the wrong place.