Lately my 19 month old son has been having severe meltdowns every time daddy is around - when he comes home or enters the room. He will be calm & content playing independently and then catches sight of his daddy and totally freaks out if daddy doesn't drop everything and pay attention to him. He screams, cries and yanks on daddy's hand to get his attention (in total admiration). We're at the point that it's just easier for me (the stronger, "enforcer" parent) to deal with him & have daddy (more of the pushover) leave the room or not participate in certain routines so as to not "give in" to our son's strong desire to be with daddy. We're not sure whether or not it is beneficial for daddy to try and be around him but ignore his fits (especially when he wants daddy to follow him EVERYWHERE he goes) or if it's better for mommy to deal with it & for daddy to leave the room. It's flattering that he's so crazy about his daddy, but we're not exactly sure if it's just a phase or if something else is going on. Any input you may have to help us handle his outbursts appropriately (which would best benefit HIM - not daddy or I), is greatly appreciated.

This is an interesting situation and one that is quite common. Sometimes the child only wants Mommy and rejects Daddy and sometimes it's the other way around. Often when a child has an anxious reaction to a parent, it has to do with attachment worries. In this case he loves Daddy but Daddy may be at work a lot. He is too young to understand this, all he knows is this wonderful person who is around me and makes me feel so good is here, and then he's gone. These comings and goings are unpredictable and he has no context, so he worries that Daddy is going to leave again and soon as he sees him. This is exacerbated when fathers or mothers travel extensively or works very long hours. The reverse can also happen where children are clingy with their mothers and see the father as someone who comes along and interrupts Mommy time.
 
So here's what to do. Instead of keeping Daddy away, which is most likely aggravating the situation, try doing the opposite for a little while. If you are always pulling your son away and taking over, he will escalate his behavior in protest, and become increasingly anxious. Try, when he wants Daddy or Daddy is not paying attention to him, to reflect that back to him by mirroring (my book Connected Parenting explains how to do it and it really defuses and deescalates kids).  For example Instead of saying, " You'll be fine, Daddy will be here in a minute. You still have me--don't you love me?", try the opposite. Try saying, "You want Daddy, you see me all the time and it's Daddy you want, you love Daddy, I love him too, I can see why you want to be with him." This way he will see that you have understood his message and the urgency of it. This makes you the ally, not the enemy, so you can work together on the issue. 
 
Have Dad spend some focused time on him for a few minutes as soon as he gets home without doing anything else. We are often tempted after a long day to read the mail, the paper, or check emails. Our kids then bug us or escalate their behavior. So have your husband spend uninterrupted time with your son as soon as he gets home. You can be there too, so you are part of the fun and he sees that. They can tickle play and wrestle for about 20 to 30 minutes then Daddy can go and do what he needs to do. Most of the time kids feel that they have gotten what they need and will accept it. If he gets upset, try mirroring; that should de-escalate & calm him. Reassure him that he will get through it and be okay and there will be more Daddy time later. Of course there will be times that your husband can't focus on him and has other things to do. That is reality and he will have to learn to deal with it. You may have to just stay neutral -- go about business as usual and ride it out a bit like you have been,  but with the mirroring.  "Daddy time" should go a little easier and you should see him dealing with it better and getting over it faster.

It is also important for you to make sure your bond with your son is nice and strong, and doesn't get frayed from all these Daddy meltdowns that you have to handle. Spend your own focused connecting time every day -- once or twice for 10 to 20 minutes. It will really help. I know as parents we think we do this already but you need to do it that little bit more, in a focused way. Look into his eyes, baby him, and tickle him. Feel the connection strengthen and things should even out and settle down nicely. Good luck.