Pop megastar Taylor Swift endorsed Kamala Harris on Tuesday after her debate against Republican rival Donald Trump, calling the Democratic nominee a “steady-handed, gifted leader” who could lead the country with calm rather than chaos. In a post on Instagram, Swift told her over 280 million followers that she will vote for the US vice president in the Nov. 5 election, in the biggest celebrity endorsement yet for Harris. Polls show the race essentially tied between the two candidates. “I will be casting my vote for Kamala Harris and Tim Walz in the 2024 Presidential Election. I’m voting for @ka…