Can attack ads against Trump be effective?

I am very frustrated by the news media repeatedly stating that the attack ads against Trump have failed because they were published too late.  I am of the opinion that one reason people are buying into the Trump message is that he has been repeating the same message daily since last June.  In addition, the media replays his daily message multiple times each day.  It is as though people have been placed into a trance in which they chant, “Yes, Donald is right.  Donald will take care of us.  Donald is our savior. I must vote for him!”  
I believe that between now and the general election, the news media should follow every clip of Donald Trump spewing his vitriol with a clip of an attack ad against Trump and state who is funding the attack ad and why.  This way the public could be reminded frequently that there may be more than one perspective on who should be elected to lead our nation.