One of the most common questions people ask political cartoonists is where we get our ideas. The late Jeff MacNelly used to say we have the greatest gag writers in the world working for us in Washington, D.C. and he had a point.
Cartoons often start with a news item and then the cartoonist adds his opinion.
For instance, when I read that the Democrats were carefully crafting their case for impeachment I wondered why they were wasting their time; the Republicans were going to trash it once it got to the Senate.
So you think of a metaphor that makes your point visually and this is what I came up with.