Once a president. Always a president. It's not about fealty. It's about respect. Despite my dislike of many a former president, I see no problem with acknowledging their past services to the country. To be clear, the Office of the Presidency is one of servitude to the people of the United States (at least it was originally conceived to be.) When the current and former presidents get together, they are all Presidents. President Trump, President Obama, President Bush (Jr.), President Clinton, Present Bush (Sr.)... I admire some and I vehemently hate some. But I will still show them the respect of their current or former Office by referring to them all as "President". So Happy Birthday, President Barack Obama.