proxies = reasons?

[Herb Stahlke]

Christopher Beam writes in Slate
(http://www.slate.com/id/2262668?wpisrc=xs_wp_0001):

"Looking at the primary results, though, you never would have known.
Doomsayers in 2010 could point to proxies for incumbent losses—a bad
economy, low presidential approval ratings—but again, those factors
tend to work against the incumbent party, not so much incumbents
across the board."

He seems to be using "proxies" to mean "reasons," or, in his own
words, "factors."  OED, Free Online Dictionary, MW Online, and Urban
Dictionary give no definitions close to this.

Herb

------------------------------------------------------------
The American Dialect Society - http://www.americandialect.org