We love it when voters take over the narrative, and that’s what will happen in Iowa on Tuesday night as voters meet to caucus and choose a possible presidential nominee. Here’s what we’re watching.

How will social conservatives split?

Conventional wisdom had it that the anybody-but-Romney crowd might go for as many as four of the six candidates looking for a ticket out of Iowa. Will these voters coalesce around a single alternative, or will they decide that electability matters more and throw their support behind Romney?

Will Ron Paul shake things up?

Paul polled well in the summer straw poll, and he appears poised to perform well again. But will his voters--a committed and engaged band of Republicans who cherish his brusque style, stay true? Jon Stewart famously noted that Paul’s victories are treated like the 13th floor of a hotel--as if they’re not there. But that could change now.

Do surges matter?

After soldiering through a volatile year in which nearly every GOP candidate vaulted briefly into the lead, we are reminded once again that a steep rise often translates into precipitous decline. Rick Santorum’s last-minute bounce will have to retain enough buoyancy to boost his fundraising in the short-term to prepare for the attacks on his record that are sure to come.

The 25 percent solution

Mitt Romney has never managed to snag the undivided loyalties of more than a quarter of the likely caucus-goers. In a divided electorate, that might be enough for now. But as the field shrinks, some of those voters will have to come home to the front-runner, or he will spend precious time, energy and money uniting the party, rather than tuning up for an Obama challenge.

What will Democrats do?

Yes, Virginia, there is a Democratic contest going on. Even though no one is seriously challenging President Obama’s nomination, his forces have opened eight offices in Iowa--more than any other candidate on the GOP side--and are hoping to lay the groundwork for a strong general-election network. The goal: to flex muscles whenever they can and send a potent signal to independents and disengaged Democrats. And just in case they’re not paying attention? The president plans to send a live video message to caucus locations on Tuesday night. Iowa is considered a battleground state and has six important electoral votes that Obama is hoping to retain this year.

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