Viewer’s guide: Stakes for the 7 candidates in GOP debate | McClatchy Washington Bureau

The first Republican presidential debate of the new year Thursday kicks off the campaign’s serious – and uglier – season, with the smallest GOP field yet.

The 9 p.m. EST faceoff on the Fox Business Channel will include just seven top-polling contenders, a small enough group to allow more elbow room for those on stage. With voters getting ready to start making their choices in just weeks, every charge and countercharge will be magnified. Already since the year began, the personal side of the campaign has escalated with questions about Ted Cruz’s citizenship, a pro-Jeb Bush ad mocking Marco Rubio’s high-heeled boots, and Chris Christie accusing Rubio of a “slime” campaign.

On the main stage, the top tier will include real estate mogul Donald Trump and Sens. Cruz of Texas and Rubio of Florida. Also, four others in a fight for survival: New Jersey Gov. Christie, former Florida Gov. Bush, Ohio Gov. John Kasich and retired neurosurgeon Ben Carson.

A 6 p.m. debate will feature Republican contenders whose poll numbers were not strong enough to make the main stage: former Arkansas Gov. Mike Huckabee, former business executive Carly Fiorina and Rick Santorum, a former U.S. senator from Pennsylvania.

Sen. Rand Paul of Kentucky, dropped from the top debate, declined to attend the undercard event.

The stakes for the top-tier candidates:

Trump. He’s got to show he can talk seriously about policy, perhaps with talking points that show he has some idea of how he’ll implement his ideas. At the same time, he has to keep showing the trademark bluntness that’s endeared him to a lot of voters who appreciate his ability to express his frustration with government and politics.

Cruz. He’s been slipping, rattled by questions about whether his birth in Canada disqualifies him from the presidency. The latest Bloomberg Politics/Des Moines Register Poll showed Trump gaining in Iowa, though Cruz remains ahead. Cruz needs to continue offering his sharp, well-defined remedies for turning the government more conservative and making America look tougher against the Islamic State and other national security threats.

Rubio. He needs to generate momentum, give some reason he’s different from the rest. Being thoughtful, serious and visionary hasn’t been enough. Rubio could find himself on the defensive, as Bush and other center-right candidates see themselves gaining if Rubio falters.

Carson. Can he rebound? It doesn’t look promising. Previous debates helped trigger Carson’s collapse, as he was unable to show much confidence in or knowledge about national security matters. He’s shaken up his campaign staff and retains a solid core of Iowa loyalists who have been working for months to get him elected. But Carson badly needs a big night to get back on track.

Bush. Bush’s strength is his depth of knowledge on policy, but he tends to go on and on. If he can offer easy-to-understand ideas, he could have a good night. He could be taking a risk in being too sharply critical of Trump and Rubio; it may make him look like a standard-issue politician. Bush can do better.

Kasich. He’s become a favorite of New Hampshire’s center-right, and it may be paying off. Kasich’s brash, unpretentious style has sparked criticism in previous debates, but it sells on the campaign trail, and he’s proven he can win in a diverse state. Chances are viewers will see more of Kasich’s signature style Thursday.

Christie. The other brash center-right candidate, vying with Kasich for a New Hampshire breakthrough. Christie has been firing away lately at Rubio and Trump, and he’ll probably keep that up Thursday. He needs to offer policies, though, that differentiate him from Kasich and Bush, and so far he’s had a rough time. He needs to come out of the debate with an idea or two to remember.