Former President Trump is back on X, the social media platform formerly known as Twitter, seeking to expand his audience at a time when he’s losing ground to his new opponent, Vice President Harris. Trump had posted 18 times between Sunday morning and Tuesday evening on a host of topics to his 90 million followers on the site. The former president has used the site to blast Harris — at times dubbing her Comrade Kamala — on issues from inflation to fracking and the Middle East. In one missive,...