JSFiddle - React, Tailwind, and code Playground

HTML

<h1>Hello World!</h1>
<h2>I'll marquee twice</h2>
<h3>I go fast!</h3>
<h4>Left to right</h4>
<h5>I'll defer that question</h5>

JavaScript

(function($) {
        $.fn.textWidth = function(){
             var calc = '<span style="display:none">' + $(this).text() + '</span>';
             $('body').append(calc);
             var width = $('body').find('span:last').width();
             $('body').find('span:last').remove();
            return width;
        };
        
        $.fn.marquee = function(args) {
            var that = $(this);
            var textWidth = that.textWidth(),
                offset = that.width(),
                width = offset,
                css = {
                    'text-indent' : that.css('text-indent'),
                    'overflow' : that.css('overflow'),
                    'white-space' : that.css('white-space')
                },
                marqueeCss = {
                    'text-indent' : width,
                    'overflow' : 'hidden',
                    'white-space' : 'nowrap'
                },
                args = $.extend(true, { count: -1, speed: 1e1, leftToRight: false }, args),
                i = 0,
                stop = textWidth*-1,
                dfd = $.Deferred();
            
            function go() {
                if(!that.length) return dfd.reject();
                if(width == stop) {
                    i++;
                    if(i == args.count) {
                        that.css(css);
                        return dfd.resolve();
                    }
                    if(args.leftToRight) {
                        width = textWidth*-1;
                    } else {
                        width = offset;
                    }
                }
                that.css('text-indent', width + 'px');
                if(args.leftToRight) {
                    width++;
                } else {
                    width--;
                }
                setTimeout(go, args.speed);
            };
            if(args.leftToRight) {
                width = textWidth*-1;
                width++;
                stop = offset;
  ...