Democrats hate to let the mask slip. If they openly discuss their true beliefs, they lose elections. That's why every Democrat runs on lower taxes, a stronger military, and more efficient, streamlined government. If they went out there and said "We want to tax you at somewhere between fifty and seventy percent, make you a cradle-to-grave slave to your government, and weaken the U.S. in an effort to re-balance the world," they’d be buried under an electoral landslide every single time.
The only time they really tell you what they think is when they're caught by a hot mic or a hidden camera. When they think no one's looking, they're more than happy to tell you what they want to do to the country.