The truth is needed from the president. Trump's convention statements were not lies. Some statements were taken from smaller sets of data rather than overall, larger sets of data. Government officials pick and choose statistics as they see fit. It doesn't mean they are lies. They are just chosen over other statistics.
I agree that truth should be a given when it comes to the President, but every single elected official lies. There have been plenty of misleading statements and lies given by Hillary too, most recently the lie that she did not use any classified information on her private email servers. This was proven false by the FBI.
The President is the leader of the free world. The people of the United States ultimately wish to feel safe. They want to know that someone is looking out for them and that their leader cares for their well-being. America's citizens cannot feel safe if they believe that they have been lied to or duped. Dishonesty leads to the feeling of betrayal. In order for citizens to feel this safety and security, the President needs to report correct information. If they are given correct information, they will have have more faith and confidence in their leader.
If Trump is misleading the American voters before he is elected, I don't think he's going to stop misleading people when he is the President. Information travels so fast now, and so much information is available with a simple search, that there is no excuse for presenting misleading statistics. He needs to own up to what he did and apologize.