Edit in JSFiddle

$("div.learnmore").each(function (i, l) {
    pre = '<p class="label">Learn More</p><div class="learnmore inner">';
    post = '</div></p>';
    l = $(l);
    if (l.children("p.label").length === 0) {
        l.html(pre.concat(l.html(), post));
    }
});

$("div.learnmore > p.label").click(function () {
    $(this).siblings(".inner").toggle();
});

<div class="learnmore">This is the explanatory text. There probably should be a lot more text here, but I'll keep it simple for the moment.</div>
<div>
    <p>This is just a random paragraph to take up space</p>
</div>
<div class="learnmore">This is a second set of explanatory text that has its own Learn More text to click to hide/show</div>