HELP: Why are get_template_part and conditional tags breaking my code?

I have a block of HTML that shows up in several places across my theme…

<header class="row">
	<div class="headline"></div>
	<hr>
	<div class="subhead"></div>
</header>

Instead of repeating myself I decided to drop my code into a file called headline.php and use get_template_part( 'headline' ) to call my code where I need it without being redundant.

Then I add a statement to update my values according to the page being display.
Now headline.php looks like so:

<?php if (is_home()) {
	$the_post 	= get_post(2);
	$headline 	= $headline->post_title;
	$subhead 	= $headline->post_content;
} elseif (is_single()) {
	$headline 	= the_title();
	$subhead 	= the_content();
} elseif (is_search()) {
	$headline 	= "here is the headline for search";
	$subhead 	= "here is the subhead for search";
}
else {
	$headline 	= "here is the default headline";
	$subhead 	= "here is the default subhead";
} ?>
<header class="row">
	<div class="headline"><?php echo $headline; ?></div>
	<hr>
	<div class="subhead"><?php echo $subhead; ?></div>
</header>

I assumed this would work. However, when I refresh my page, <div class="headline"></div> and <div class="subhead"></div> are empty.

Am I missing something? Can someone tell me what I’m doing wrong?