JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://documentcloud.github.com/underscore/underscore-min.js"></script>
<h3>Example1: No Template</h3>
<div id="example1_no_template"></div>

<h3>Example1: With Template</h3>
<div id="example1_template"></div>

<h3>Example2: No Template</h3>
<div id="example2_no_template"></div>

<h3>Example2: With Template</h3>
<div id="example2_template"></div>

<h3>Example3: Really Strange Behavior Using Template</h3>
<div id="example3_template"></div>

<script id="template1" type="text/html">
    <%= message.replace(/\r?\n/g, '<br />') %>
</script>

<script id="template2" type="text/html">
    <%= message.replace('\n', '<br />') %>
</script>
        
<script id="template3" type="text/html">
    <%= message.replace(/[\r\n?]/g, '<br /><br />') %>
</script>

CSS

h3{font-weight: bold;margin:10px 0;}

JavaScript

var message = 'Line1\r\n\r\nLine2';

$('#example1_no_template').html(message.replace(/\r?\n/g, '<br />'));

var template1 = _.template($('#template1').html());
$('#example1_template').html(template1({ message: message }));

$('#example2_no_template').html(message.replace('\n', '<br />'));

var template2 = _.template($('#template2').html());
$('#example2_template').html(template2({ message: message }));

var template3 = _.template($('#template3').html());
$('#example3_template').html(template3({ message: message }));