Almost everything he has done has been to hurt the economy, instead of helping it. Bailing out private companies at the expense of tax payers and in favor of unions (like GM). Preventing oil drilling here (Gulf of Mexico) while encouraging it elsewhere (Brazil). Increasing ethanol mandates in fuel, even for military jet fuel, while we see food prices rise as we burn corn in gas tanks, though ethanol is net energy neutral when it comes from corn.
Prohibiting the Keystone gas pipeline, though it would create thousands of high paying union jobs immediately, so Canada sends the oil to China instead. Shutting down coal mining and coal fire power plants, driving up power costs for all while killing many jobs. Punishing GIbson Guitar for violating an obscure Indian law on labeling and shipping eco-friendly wood. Promising to focus like a laser beam on jobs, then using a deem and pass to pass a bill on mandating health insurance, while it drives up the costs of healthcare policies another 2500 per family after promising costs would go DOWN - and still exempts illegal aliens from having coverage or paying their health care bills.
There are other things, too,but that's a short list.