Think it's silly to pretend that conservatives are the only people who disdain unions. If 90% of American workers favored unions they'd be much more prevalent. More people would rather be judged on their individual merit/productivity than their length of employment. Was painfully obvious that Chris Paul was Wake's (if not the ACC's) best player the moment he stepped on the court as a freshman, not some random senior.
In 2007, a year before GM filed for bankruptcy, their legacy pension/healthcare burden per car was $1700, before material costs and labor were even added in. Having 18 year olds who finished last in their high school class join the union at 18, work 30 years, and retire with full benefits at 48 was no longer sustainable. Most private companies phased out fixed retirement benefits in the early '90s because they realized the ongoing liabilities weren't sustainable.
Globalization has more to do with declining incomes than lack of union participation. The cost difference between union Detroit labor and non-union South Carolina or Alabama isn't the problem, it's the difference between Chinese or Malaysian labor and US labor (union or non-union). Two thirds of American GDP is retail spending and Americans aren't willing to pay $1000 for US-made iPods, $5000 for iPads, and $10000 for desktops.