The argument that the homosexual political movement is indebted to the label 'gay' is most tenuous. Even if it were granted, it is hardly justification the abandonment of the much more sterile term atheist. Furthermore, I think that if you consult the popular culture, you will discover that, contrary to feelings of happiness and giddyness, the term 'gay' has become quite stigmatized and conjurs up images of debauchery, effeminancy, amorality, lasciviousness, ineffectuality, and all the other manner of prejudice in the minds of those the movement seeks to persuade, even to the point where the term has fallen into disuse. The political success owes less to the connotative vagaries of the term and its power of suggestion, than to the ability of a single inclusive name to induce unification and constituent organization.
If political influence is what you seek, perhaps the terms atheist and freethinker are ill-equiped for the task, having not the potency to draw all manner of disbelievers into a single fold. Yet it seems to me that 'Bright' offers no better solution and worse, could promote division within and without the ranks, by virtue of the very implications inhering in the name. The suggestion of intellectual superiority is no small matter and would engender feelings of hostility rather than attractiveness among the opposition. The 'gay' political movement was well aware of this and chose a politically inclusive rather than exclusive label. 'Bright' fails on this account, ever so miserably.
I'm happy with atheism as an intellectual movement. As such, it is free from the political manuevering and manipulations, and is beholden to none other than reason herself. Nevertheless, I recognize the need for political organization and, not wishing to malign the good name of freethinker, I concur that there is need for a political label through which an atheistic political agenda could be pursued. For this purpose, bright is ridiculously impoverished and impotent for reasons explained above. The appropriate term must be politically inert, and it must be socially inclusive. I leave its conception to you.
