I would say most people associate the democratic party with blue collar workers, unions yes but not just unions.
Although I was trying to stay more generic and not go dem/pub... Oops.
You cannot stay generic because liberals act through the Democrat party, and the actions of the Democrat party defines what liberals are for, and what they are against.
The Boeing move to North Carolina pitted union workers against non union workers, and the Obama administration took the side of the union workers. Most liberals here supported the administration. Nor, has the Democrat party done anything in the last thirty years that showed they favored any non union workers. Blue collar or otherwise.
In addition, blue collar and white collar workers have been voting with their feet against the unions, while the Democrat party has worked to allow unions to force them back in.
Liberals are not pro-worker, regardless of what they like to think of themselves.