I want to apply select2 to a bunch of jquery elements on the page that all have the same class name but it looks like if i call select2() on an element that already has had
Above answer is almost correct.
But it creates problem when we are adding elements dynamically on same page and applying select 2 to newly created element.
At that times selector has to be specified using not only class but also with input type. PFB reference code.
$('inputp[type="text"].MyDripdowns').each(curr_idx, curr_elem){
//Check if select 2 is already applied or not
if($(curr_elem).hasClass('.select2-offscreen')){
//Select 2 is already applied to this element
}
else{
//Apply Select 2 to this element
}
}