It fits the pattern of her misguided anti-gun laws. I think the implications don't matter to her, so long as the legislation resonates emotionally with uninformed voters.
(EDIT: To clarify: from a rational perspective, some of her sponsored anti-gun laws primarily have the effect of alienating and galvanizing the opposition with nonsensical and ineffective laws. From a rational anti-gun perspective, they have done more harm than good.)
You can look at the legislature like a biological ecosystem subject to evolution. The natural selection force that acts on it is election ("natural election"?). Legislators who do not get elected do not survive in the ecosystem.
That means the direct evolutionary pressure is for legislators who focus on re-election above all else. Any actors who have different priorities are quickly outcompeted and kicked out of the gene pool.
You could look at insulation like it's made of whipped cream, but that doesn't make it a good pie topping.
In other words, government officials are not in fact bound by the rules of natural selection whatsoever, and they can live perfectly comfortable, happy lives without getting reelected.
What's evolving due to natural selection in the gp comment is not Diane Feinstein nor any other member of Homo sapiens. What's evolving are patterns of behavior of legislators and elected officials. Dawkins memes as received wisdom on how to be a Congressperson or Senator.
I suggest you check your premises.