Intermittent Static pops in one channel

When playing vinyl, a new recent thing has developed over the last month. I've noticed that I've been getting an increasing number of static pops only in the left channel. Almost never seems to cone from right channel. This really iisn't distortion (too much anti-skate), but frequent static like pops and clicks.

Cleaned stylus, using anti-static brush, and washing records hasn't really helped. Rechecked stylus alignment and azimuth to no effect. Any ideas? Thanks in advance for any suggestions.