The phrase "bald assertions" refers to statements or claims made without any evidence or supporting facts. These assertions are made without any proof or backing, and are therefore unreliable or untrustworthy. Full definition
''... insist on religious leaders making their case by reasoned argument not by bald assertion or authoritarian claims.» (religion.blogs.cnn.com)
Whenever logic starts hitting to close to home, you run back to your question begging and bald assertion corner and start whining that pretty please, you just got ta be right because, because, because.. (religion.blogs.cnn.com)
This allegation just strings together antitrust buzzwords and offers the sort of «bald assertion [s], without any supporting allegations,» that do not survive a motion to dismiss. (theregister.co.uk)