What is a word/phrase to describe someone who thinks someone else is perfect? For instance, if parents think that their child can do no wrong, then they are . . .? (Not necessarily biased or partial, because it is not in comparison to anyone else)
At the risk of being a bit too obvious, there is always Awestruck, which, quite literally means
Filled with Awe
It's not necessarily an appropriate term to use for parents who think their child can do no wrong - but then, I wouldn't describe that as Awe.
Now a child who thinks their parent can do no wrong- that's a strong use of both 'awe' and 'awestruck'.
I would suggest Adoring
from adore: to regard with the utmost esteem, love, and respect; honor. (Dictionary.com)
How about adulation?
excessive or slavish admiration or flattery
fill (someone) with great delight; charm.
"Isabel was enchanted with the idea"
synonyms: captivate, charm, delight, enrapture, entrance, enthrall, beguile, bewitch, spellbind, fascinate, hypnotize, mesmerize, rivet, grip, transfix
I think Idolizing is probably the best fit, but it seems that you're looking to place an adjective/title on the people that perform this behavior then it would be more appropriate to say that they are idolizers. Here are a couple other options in the same neighborhood:
Venerator - A person that regards or treats with reverence; revere.
Fanatics - could also be another consideration as that has an implied sense of blindness to negative qualities
Regard or represent as perfect or better than in reality
Orwell was indeed unsociable, anti-feminist and homophobic, but only ambiguously anti-Semitic, and by no means such a dewy-eyed idealiser of the plebs as some have imagined.
(def and example from ODO).
It doesn't work that well if you want an adjective, but you could use a participle:
A cognitive theory perspective emphasizes that idealizing parents may cause the child to develop an overactive view of the self that includes inflated beliefs of personal uniqueness and self-importance. In this approach to child rearing, the parents may systematically deny or distort negative feedback to their child.
from: Narcissism in the Workplace: Research, Opinion and Practice by Andrew J. DuBrin, Edward Elgar Publishing, 2012
possessed by a foolish or extravagant passion, esp for another person
I think you might be looking for the idiom rose-colored glasses
- (idiomatic) An optimistic perception of something; a positive opinion; seeing something in a positive way, often thinking of it as better than it actually is.
Guy1: Jeez, that child is ransacking the bounce-house!
Guy2: Try telling that to the parent wearing the rose-colored glasses.
Guy1: Yeah, that parent never sees any fault in their child.