This story was initially broken by the Daily Caller, it was then taken up belatedly by Fox News. The initial response from Menendez was somewhat similar to that of John Edwards to allegations by the Enquirer, Edwards ended up in Court. Both cases involve malfeasance in public office, both involve financial wrong doing and both would appear to revolve around sex. That said they are in many ways no worse than many powerful men on both sides of the Political Spectrum, for me, however what makes Menendez's case worse even than Edwards is the involvement of underage girls in a poor country.
When this broke he lambasted the news outlet that exposed him, it looks increasingly that this man has much to lose and must be made to pay.