<iframe width="580" height="385" src="https://www.youtube.com/embed/37Akzc_s3LQ?hl=en" frameborder="0" allowfullscreen></iframe> <br>The public acknowledgment of defeat by losing candidates has been a staple of U.S. presidential elections since 1896. And so far, President Donald Trump has ... <br><a href="https://www.youtube.com/watch?v=37Akzc_s3LQ">source</a>