Based on issue polling, we know that a majority of people who are opposed to the individual mandate also strongly support a ban on pre-existing conditions clauses. And also those same people oppose any form of universal healthcare.

But abstaining from health insurance right up until the point where you need it is the same as having other people pay for your healthcare. A ban on pre-existing conditions without an individual mandate is a form of welfare. So in actual practice many people who are nominally opposed to universally subsidized HC are in fact not opposed to universal subsidization of healthcare... as long as there's some nominal involvement with the insurance industry prior to use.

The broader point: many people don't realize that just because you're paying into something doesn't necessarily mean it isn't welfare. In a democratic society with a lot of individualism and distrust of government, sometimes this "hack" is the best way to deliver a welfare state. See also: social security.