yea the router seems like a strange thing to want other than to see if the traffic could be routed. the routers I have seen never keep a copy of the traffic, or even a log of what type of traffic was sent/received.
The firewalls might tell you more, and would tell you of the elections network traffic was segmented off and or restricted.
Most enterprise routers are not the vpn provider. Either the firewall or a dedicated VPN appliance/server provide VPN access.
Every configuration is different, but generally routers only have the routes, they don't police the traffic other than to limit routes.
Even if a router is compromised, most of the infrastructure to enforce traffic rules is elsewhere.
What would you hope to find on a router other than that the network is not configured to enable the network to be secured using other tools?