Ted Cruz, now locked in a struggle to the political death with reigning campaign champion Donald Trump, faces a make-or-break night at the GOP debate Thursday night.

Proving his mettle as a candidate worthy of his post-season position, Cruz has ruggedly endured a sustained week of media battering over Trump’s birtherism blitz, losing little ground.

Trump’s all-out offensive that raises questions about Cruz’s eligibility because of his birth in Canada – widely held to be a non-issue by constitutional experts — has arrested Cruz’s upward momentum but not caused a collapse. But while Cruz has barely dropped in the polls as a result, he cannot merely survive under siege from Trump if he means to win the nomination.

More from LifeZette TV

MORE NEWS: PA Supreme Court Rules Mail-In Ballots May Be Counted Three Days After Election

That is where Thursday’s GOP debate hosted by Fox Business News comes into play.

Cruz desperately needs to change the conversation — and the dynamic of the last several weeks. He needs to find a way to balance his previous semi-alliance with Trump with a strategy to throw the front-runner off his back.

Do you agree that protesting is acceptable, but rioting is not? Yes No Email Address (required) By completing the poll, you agree to receive emails from LifeZette and that you've read and agree to our privacy policy and legal statement Results Vote

Cruz made it to the playoffs of the GOP contest by riding in Trump’s wake. He has campaigned on the substance of Trump’s rhetoric and played the role of the more serious choice for voters attracted to the populist mantra of putting American workers and interests first.

Now under fire from Trump, Cruz can no longer bank on the steady stream of incoming support, a strategy that worked earlier in contest. Cruz must take command of the narrative in Thursday’s debate and, going forward, in the 2016 primary contest, by controlling the narrative.

The Texas senator can best move to flip the conversation of the race by adding a new angle to a theme already present in his longtime messaging. The media is the enemy of conservatives, and of populists, and the ally of Trump, who plays the media like a fiddle. Cruz can tie the Trump birther attack to the frenzied media that have sustained it, and draw the connection for Republican primary voters that the media works for the Democrats — and the Democrats want the media to crush Cruz and raise Trump.

MORE NEWS: Maine Police searching for woman who left dog poop in mailboxes of Trump supporters: Defaced campaign signs

In this championship game, Cruz must call out Trump for what many conservatives can be convinced to see as an unholy alliance with the liberal, mainstream media. An alliance Cruz can claim now aims to kill him off, in order to protect Hillary from facing him in the fall.

Donald Trump, who has spent very little money on his campaign, has been the undisputed master manipulator of the media since he first entered the GOP contest. To truly defeat him, Cruz must deprive Trump of the unfettered benefit he reaps from that asset.

The media-based counter-attack is ideal for Cruz in that it casts doubt on his largest negative liability to date, the birther charge, while linking the inherent mistrust conservatives have of the media to Trump. And it can work to dull all further Trump media spectacles targeted at the Texas senator.

Media mastery is the core strength of Trump as a candidate, with other appealing assets falling into place underneath that one major forte.

But that has only been tested through the course of a GOP primary. Cruz should pose the question during Thursday night’s debate about what happens to that ownership of the media in a general election matchup with Clinton.

Sure, the media salivates to cover Trump’s jabs, insults and insinuations towards other Republicans. But a biased liberal media is highly unlikely to allow that control of the conversation to continue against Clinton.

To tie up Trump with his own net and paint himself as the sole, pure populist against the world may be the key for Cruz to ultimately win the nomination.