Let's see . . . what happened in 1998? [tapping fingers]
I got it! A recession! Shortly afterward, your typical protectionist (you can identify them because they never provide proof of their assertions) discovered that he can blame out-sourcing, even though it has been going-on for decades. Add a little bit of economic ignorance, mix well with anecdotal evidence and you have a nice collectivist stew. Simmer on low heat, and don't forget to call anyone who questions you a traitor.
Ummm...there was NO recession in 1998. '98 was one of the hottest years of the boom and it made many people, including myself, quite wealthy.
The economy didn't start turning until 1999, and we it didn't enter a recessionary stage until 2000. The flattening of median income began BEFORE the rest of the economy tanked.