Five for 2012, debate edition:

— “NoBama” is the word. Corroborating fake news from The Onion, a message-testing experiment conducted on Facebook by SocialCode (a subsidiary of The Washington Post Co.) finds a straight-ahead anti-Obama message is the most effective way to get Iowa and New Hampshire Facebook users to “like” Republican presidential hopefuls. Negative ads citing “Obamacare,” the economy and values pulled somewhat less weight.

— Herman Cain, Rick Santorum and Tim Pawlenty may need an introduction. At least four in 10 Republicans expressed no opinion when asked if they’d consider supporting Cain (50 percent no opinion), Santorum (48 percent) and Tim Pawlenty (45 percent), according to a June Post-ABC poll. By comparison, just 13 percent had unformed views of Mitt Romney; 15 percent of Newt Gingrich.

— What matters to GOP voters? Look for positive references to Medicare reform and the tea party. More than four in 10 Republicans and GOP-leaning independents in the most recent Post-ABC poll said they are more likely to vote for a candidate who supports major changes to Medicare, compared with 21 percent who view this as a negative factor in their vote. Republicans said support from the tea party movement is a positive factor by a 31 to 14 percent margin. A challenge for Gingrich in the survey conducted just before his staff shake-up: 54 percent of Republicans said they would be less likely to vote for a candidate who has had an extramarital affair.

— Romney leads debaters in polls. More than one in five Republicans and GOP-leaning independents – 21 percent – pick Mitt Romney as their top choice for the Republican nomination, according to the June Post-ABC poll. No other candidate on stage Monday night in Manchester, N.H., wins more than six percent support in the recent poll. Sarah Palin, who will not participate in the debate, garnered 17 percent support in the Post-ABC survey.

— Republican jury is out on Romney and health care reform. Almost twice as many Republicans oppose the health care reform plan that Romney put into place in Massachusetts than support it (41 percent oppose, 21 percent support), according to the June Post-ABC poll. But fully 37 percent have no opinion on the issue that has become a point of attack from some of Romney’s rivals.