Would be interesting to chart this with a color code of how 'red' or 'blue' a city is.   

Still, I would start with blue collar neighborhoods for your first few rentals.

I have the Homan bus stop on my block, Roosevelt Rd Bus about a block away, and I-290 and Blue Line less than a mile north of me, not to mention Douglas Park which is now starting to attract music festivals and other positive events, which can someday attract potential (responsible) renters and/or buyers.

I would look to the south end of Topsail Beach -- I anticipate strong appreciation/growth due to some unique factors such as crystal blue water and a highly successful beach renourishment program.

Blue, purple, green and yellow carpets with matching (yes matching blue, purple, green and yellow) wall mounted toilets and bedroom paint jobs.

If you like blues then try listening to the Playing For Change music on youtube.

TC is definitely a very plant/blue collar based city.

I owned a rental cabin in blue ridge briefly and then flipped it because it was very remote and needed completely furnished.

I would agree with @Shannon Sadik that Blue Axis is a great company (Rebecca manages all 31 of my units) but she tends to stay out of the C and below areas.

The more working class blue collar type neighborhoods are west and southwest of the Riverside / Avondale / Murray Hill neighborhoods.