A few notes from the campaign trail yesterday. In addition to Paul, I saw three other candidates — Michele Bachmann, the surging Rick Santorum and the presumptive front-runner Mitt Romney. Each candidate argued that Iran posed a grave threat to America and the world. Bachmann vowed that if she were president, she would not preside over a nuclear Iran that targeted American cities. Santorum, in a creative reading of a Washington Post article yesterday, said that Iran was setting up terrorist training bases in South America. And Romney claimed that Obama was lying down, rather than standing up, in the face of the Iranian threat.

Both Santorum and Bachmann attacked Paul harshly — Santorum because of Paul’s insufficient defense of gun rights and the sanctity of the unborn, and Bachmann because of Paul’s irresponsible and dangerous view on American foreign policy. Incidentally, I was curious about Santorum’s attack on Paul’s abortion record, so I looked up some of his interest group ratings. In the last Congressional cycle, the National Right to Life Committee gave him a 100% rating, though it was somewhat lower than that in previous cycles.

Santorum, who is a close third according to polls released yesterday, told a crowd at a Pizza Ranch in Jasper County, an hour east of Des Moines, touted his family of seven children and asserted that it was faith and family, not our system of government or even our constitution, that made America great. Then Santorum quickly added, “but not any type of families—men and women bonding together to have children.” Santorum, it should be noted, has spent more time campaigning in this state than any other aspirant. He’s visited all 99 counties (as has Bachmann) and held hundreds of town hall meetings. Even if Santorum were to pull off the upset tonight, he has no real shot at the presidency. But he’s staked his campaign on the hope that he could galvanize Christian conservatives here the way Mike Huckabee did four years ago. And his message was clearly calibrated to advance that appeal.

Last night, I saw a Romney rally at the warehouse of Competitive Edge, an Iowa-based manufacturing company that outsources much of its work to China. I mention this detail, because Romney spent a good deal of time last night bashing China, for “stealing our intellectual property” and other transgressions. According to a Talking Points Memo (TPM) report this morning, the owner of Competitive Edge is a Romney supporter and told TPM that he doesn’t think Romney’s attacks on China — a staple of his campaign are much more than rhetorical.

Romney’s event was certainly the most slick I’ve seen — he had a large advance team, there was a cordoned off aisle through which the candidate charged through to raucous music and applause and in word and bearing, Romney acted the part of the presumptive nominee who was best positioned to knock off Obama in the general election. He attacked Obama on jobs, on regulations, on debt and promised to end Romneycare—oops, I mean Obamacare—on day one (sorry, couldn’t resist).

He also added that this election would come down to two very different visions: one predicated on the principles of our founding fathers and a merit-based opportunity society, and one based on European social democracy, “where the government takes from some to give to others.” I confess I find this particular line—another Romney staple—especially fascinating. There is certainly much to debate about the relative pros and cons of various European social welfare states compared to the American model. But if you’re trying to present to people a nightmare scenario of an intolerable future, invoking societies in which, by and large, people live longer, there’s less crime and the workweek is shorter—well, I just fail to see what precisely is shudder-inducing about that vision.

Romney may not win tonight. But it’s pretty clear the GOP nomination fight is all but over.