ngrams
一人でも多く	489717

Seems frequent enough to include.

Let me note that in general, I don't think a specific 
phrase making an appearance in a GG5 example sentence is, 
without supporting evidence, a good basis for inclusion 
as an entry. Curtis, I'd appreciate if you could provide 
additional sources as well in the future. Even if the 
expression is not in any of the other dictionaries, 
googits" or bing hits can still be helpful indicators of 
how common an expression is.

@@ -11,0 +12 @@
+<pos>&adv;</pos>

GG5="一人でも多くの有権者と握手をして支持を求めたい.　I want to (personally) shake as many voters as I can by the hand, and ask them for their support."