>One of their approaches to gain sympathy to their cause is to keep making taxes hard
I'm not sure where you get this from. People on the right have been yelling about simplifying the tax code for a long time. Flat tax, "postcard-sized tax form," national sales tax, all kinds of ideas have been floated. Even eliminating the income tax altogether and going back to funding the government through tariffs, those the people who suggest that wear a lot of tri-corn hats or subscribe to "Reason" magazine.
The fact of the matter is the tax code is the biggest trough from which politicians can reward donors, lobbyists, and other allies. A nice tax carve-out for left-handed buggy whip manufacturers is easy and cheap, and nobody reads all 1100 pages of some omnibus bill, so whoever slid it in can claim to be "for small business!" (the right), or "making the rich pay their fair share!" (the left).
As for the general population, all of their taxes are taken out of their paycheck. Taxes aren't hard for them. They pay a few thousand in income and payroll taxes over the year, they get a thousand or so back in a refund, and they think everything is great.
If there was a bill that eliminated all the tax code and replaced it with a brochure-sized alternative, there might be some on the right who would object, but EVERYBODY on the left would lose their minds. I can't think of a single progressive who has supported a simplification of the tax code.