What to Watch in Tonight's Republican Debate in Washington, D.C.

The latest GOP debate comes at a time of campaigns in turmoil and unanswered questions about foreign policy

Tuesday's Republican debate is the 11th of the year, the first to take place in Washington and the second to focus on national security and foreign affairs. As the GOP field continues to shift, a new political dynamic provides fresh intrigue. Meanwhile, the previous foreign policy debate a week and a half ago left plenty of unanswered world-affairs questions on the table. The 8 p.m. debate, co-sponsored by the American Enterprise Institute and the Heritage Foundation, will be moderated by Wolf Blitzer and aired on CNN. A few things to look forward to:

1. How long can the Gingrich detente continue? Newt Gingrich's ostentatious refusal to go negative, at least to his rivals' faces, has contributed to the polling surge he's now enjoying. And his high-minded insistence that when Republicans attack each other, only the liberal media wins, makes it that much trickier for other candidates to go after him. But how long can they resist the urge to take this self-satisfied pol down a notch or two? It's certainly possible to shatter his composure -- the one time Gingrich has been attacked in a debate, when Mitt Romney needled him for having supported a health-care mandate in the 1990s, he got testy and defensive, and ended up ceding the point. Michele Bachmann's campaign issued a press release questioning Gingrich's pro-life credentials during the weekend's social-conservative cattle call in Iowa, but Bachmann has tended to shy away from such tough talk in person. Gingrich certainly provides his competitors with a wealth of material should they wish to go on offense.

2. Is anybody going to try to stop Romney? As the time ticks down and the struggling candidates get desperate, the necessity of knocking the front-runner off his pedestal would seem to become more acute. But if anything, the other candidates have increasingly given up on putting a dent in Romney's armor. At the last debate, Gingrich was served an opportunity to repeat a criticism of Romney, and he refused -- an act reminiscent of the time when Tim Pawlenty lacked the nerve to reiterate his coinage of "Obamneycare" to Romney's face. If something like that happens again, it will be a sign that the other candidates have concluded that the debates are essentially Romney's turf -- an extraordinary concession.

3. What about Europe? The Nov. 12 foreign policy debate in South Carolina was a wide-ranging, substantive survey of the candidates' positions on such matters as Iranian deterrence, aid to Israel and troop levels in Afghanistan. But time ran out before the candidates could be asked about the ongoing fiscal crisis in Europe -- an important and a tricky subject that's likely to come up this time.

4. Did Herman Cain study? Cain's answers at the last debate were a muddle of vague excuses and promises to hire knowledgeable people. And that was before he fumbled a question on Libya in a newspaper interview -- despite having flubbed a Libya question months before. It's one thing for a non-politician who says he's a "leader, not a reader" to have a steep learning curve, but Cain increasingly seems not even to want to learn.

5. Welcome to Washington! The candidates have all, to varying degrees, taken the ever-popular tack of campaigning against Washington, and with the supercommittee debacle, the capital's failings have never been more evident. Now that they're actually in D.C., do they bother to be polite? More likely: an opportunity for fresh anti-establishment grandstanding, with the Washington Monument in the background.

Image credit: Getty Images/Alex Wong