Oh yes they can. At the moment sites like this one and others allow birthers to post (though sometimes restrict how many threads they can start), radio hosts like Levin, Beck and Hannity mostly just ignore them, politicians generally just don't comment on their claims, Fox News just doesn't cover them, etc. In short, birther conspiracies are generally ignored and those pushing them are sort of tolerated as long as they don't make a giant nuisance of themselves. The minute they become a serious detriment to the conservative cause by rejecting our nominee or making us all look batty in the middle of a campaign season, conservatives will go from ignoring them to attacking them. Once that happens it will wipe out any remaining sympathy they might have had in some conservative quarters which will decimate their ranks and leave only the truly hard core fringe fanatics - which we can safely ignore as their numbers will be so tiny as to be meaningless. Birthers get mad at hosts like Levin for hanging up on the now, just wait if they actually start threatening to vote against our eventual nominee for rejecting their birther agenda - hosts like Levin will go from ignoring them to outright condemning them.
To me this happened after the great Trump charge into the awaiting LFCOLB ambush.
Anyone who (as I predicted they would) doubles down on “it is a fraud - show us the REAL document” is already a hard core fringe fanatic who will NEVER be satisfied.
If they put out a video of 0bama (or his lawyer) directly picking up his LFCOLB from Hawaii DOH - opening up the sealed envelope and putting the document under the cameras - they would just insist (as many already do) that the Hawaii DOH is “in on it” - while simultaneously insisting that the document is an “obvious” forgery.
To me this is like claiming that 0bama conspired with the Treasury to print “counterfeit” $100 bills - and the resulting bills were “obviously” fake.
It doesn't make sense to anyone with a lick of reason.
They have already been reduced to their hard core fanatic constituency. Anyone still on-board at this point will not be swayed by evidence, logic, reason, or electoral reality.