Default [Q] Accessing phone via ADB shell with broken touchscreen (can't authenticate)

So, the touchscreen on my Nexus 4 broke this weekend. I have a new device coming in, but in the meantime I need to be able to access the device to use a few different apps and send/receive some SMS messages from it.

I found a guide on reddit (Apparently I'm not allowed to post links, but it'll be the first result if you google "How I managed to use my Android device with a broken touch screen")

It's not exactly simple, but it should work.

Unfortunately, I discovered that in order to use ADB shell commands, a pop-up window should appear on the phone to allow/disallow USB debugging. (USB debugging is enabled already, but there appears to be an additional 'authentication' step)

Unfortunately, I can't use the phone's touchscreen, so I can't unlock it or tap the notification that will allow me to authenticate the phone.

Is there a way I can get around that authentication step?

The device is unlocked and rooted.