One of the strongest Libertarian arguments against tight government controls is the law of unintended consequences. This says that things will never work out exactly as anticipated and the more complex the legislation the more unintended consequences it will spawn. Obamacare is complex and far-reaching so the unintended effects will be immense.
One of the first effects it is having is on part-time workers. One of the goals of Obamacare is to see that more people are covered by insurance. Currently, most part-time workers are not covered with part-time being defined as people working no more than 35 hours per week. When they were writing the legislation, some genius figured that if they lowered the limit on part-time hours then more people would be covered.
Keep in mind that it costs a lot more to hire a full-time employee than a part-time one. Places like restaurants and fast-food depend heavily on part-time employees. But now the definition of part-time employee is changing. Obamacare defines it as no more than 30 hours per week.
The employers have two options. One is to provide medical coverage for people. That is the intended consequence but those costs will be passed along to consumers. That will cost sales.
The other option is to cut part-time workers back to 30 hours and hire more workers. That complicates things for the employer but not as much as providing insurance would. But, it has a devastating effect on employees. They lose 1/7 of their income and now they are required by federal law to provide their own insurance.
Even colleges are cutting the hours on part-time teachers in order to cut costs.
So a change that was meant to increase coverage will instead cut people's hours.