Unless you know someone really high up, often all that networking can do you for is help get you an interview when you may not have otherwise. It's still up to you to impress each manager/interviewer.
That's not true. Many tax payed jobs are posted because they have to be by law. But, the job will already be filled even though they go through the motions of interviews (I got a job like this without networking). The world is and ugly place when it comes to money and power.
Also, state employees, their benefits, and their retirement plans (wich in CA is as high as 90% of sallary), takes away money from people just wanting to start at the entry level or the grunt troops between entry and middle management. Many High level state employees make nearly 150,000 dollars in a metropolitan area and they are retiring at 55 years of age.