Given a loose structure, if I have a hidden small pair and a threatening door card, I will raise (or re-raise if I am in late position), provided several conditions are met: Both the pair and the kicker are completely live, and I am against opponents who play draws (especially low 3-straights) too loosely. This makes passive opponents fold small or middle pairs which are beating you at the moment, and charges draws (against which you are currently a favorite).

If your opponents catch bad, your big door card gives you enough leverage to get folds on the expensive streets, and if you thin the field, you stand a good chance in any case. It's not uncommon for a hand like this to get to 6th unimproved, but your opponents have to improve to take the initiative at that point, and if you are beaten in-sight on 5th, folding out facing aggression isn't too expensve.

With an Ace in the door, for example, you can catch suited cards or another Ace to make a hand that will make folds for you, or you can catch trips and have the strength of your hand concealed, both of which are good outcomes.

You have to be wary of getting married to a hand like this, but it is a good hand against the right opponents.