It looks like we may finally have a GOP conspiracy theory grounded in reality.
Via Media Matters, here's GOP Rep. Paul Broun saying he won't sit with Democrats at the State of the Union because "sitting together being kissy-kissy" would be to fall into a "trap" designed to "silence Republicans":
If you wanna sit with the Democrats, you can. If you wanna sit with Republicans, that you can. We're going to have a conference next week and I'm gonna bring that up there. I already believe very firmly that it is a trap and a ruse that Democrats are proposing. They don't want civility. They want silence from the Republicans. And the sitting together being kissy-kissy is just another way to try to silence Republicans.
Generally speaking, Broun's conspiracy theories aren't grounded in reality, but on this, there's at least a kernel of truth: one of the byproducts of sitting together would be that Republicans will be far less likely to interrupt President Obama's speech with shouts of "you lie." To the extent that is an effort to "silence Republicans," then yes, mixed seating is a plot to "silence Republicans."