![o-Toluidine][1] 
![o-Toluic Acid][2]


[1]: https://i.sstatic.net/IrZpvs.png  
[2]: https://i.sstatic.net/nlLYys.jpg

When comparing *o,m,p*-toluidine basicities, the *ortho* effect is believed to explain why o-toluidine is weaker. But when comparing *o,m,p*-toluic acid basicities, the *ortho* effect is stated as a reason why o-toluic acid is stronger acid. I was told that the *ortho* effect is a phenomenon in which an *ortho-* group causes steric hindrance, forcing the $\ce{-COOH}$, $\ce{-NH2}$ or some other bulky group to move  out of the plane, inhibiting resonance. Then, if the *ortho* effect inhibits resonance, why is *o*-toluic acid the strongest and *o*-toluidine the weakest?
  
Where am I going wrong in my understanding of the *ortho* effect?