OFF TO THE RACES: Just how much change do Democrats want?
The big story from the AP on the Democratic side: "At its core, the divide between Clinton and Sanders is about just how much to change current economic, health care and education systems, and what the federal government's role in those areas should be. The candidates often share the same goals, but have different policy prescriptions and preferred tactics for achieving them."
And from the New York Times: "Republican leaders are growing alarmed by the ferocious ways the party's mainstream candidates for president are attacking one another, and they fear that time is running out for any of them to emerge as a credible alternative to Donald J. Trump or Senator Ted Cruz of Texas. Leaders of the Republican establishment, made up of elected officials, lobbyists and donors, are also sending a message to the mainstream candidates, such as former Gov. Jeb Bush of Florida, that they should withdraw from the race if they do not show strength soon."
A new Quinnipiac poll of Iowa shows Trump at 31 percent and Cruz at 29 percent, with Marco Rubio at 13 percent.
And a new Washington Post-ABC poll shows Trump up by 16 points nationally.
CARSON: NBC's Shaquille Brewster: "Iowa Republican Sens. Chuck Grassley and Joni Ernst will introduce GOP presidential candidate Ben Carson at two campaign events, just days before the state's presidential caucus, NBC News has learned. While the separate appearances are not expected to be endorsements, the Carson campaign hopes the events will give the retired neurosurgeon both legitimacy and momentum as he tries to close the deal with the state's voters."
CLINTON: NBC's Perry Bacon Jr. writes "Obama Really Likes Clinton. Will Democratic Voters Care?"
She's up with a minute-long ad outlining her advocacy for children throughout her career.
POLITICO writes that she still doesn't have a polished answer to questions about her email server.
She told Buzzfeed about her pitch for "love and kindness."
CHRISTIE: The Washington Post has a deep dive into his gamble to fix Atlantic City.
Not a great moment for Christie, who said to critics of his response to New Jersey flooding: "You want me to go down there with a mop?"
CRUZ: A new ad from Cruz hammers Trump's "New York values."
In a video obtained by the Christian Broadcasting Network, Cruz appears to tell pastors that Trump could be "unstoppable" if he wins Iowa.
RUBIO: The AP: "After months of promising that his campaign was on the verge of ramping up in early-voting states, Rubio appears to be following through in the Iowa homestretch. He dismisses the notion that he's changing in the 11th hour to play catch-up with rival Ted Cruz, who has dedicated significant time and resources toward campaigning across the state. Rubio has focused more on Des Moines and the state's other urban areas."
Jon Kyl has endorsed the Florida senator.
SANDERS: He said flatly last night that "we will raise taxes," but he insists that Americans would still save money overall.
A Super PAC founded by GOP donor Joe Ricketts is blasting Bernie Sanders as "too liberal."
The Wall Street Journal notes: "Going back decades, the Democratic Party has often seen presidential hopefuls find early support in the face of better-known, better-financed establishment candidates, only to later falter."
TRUMP: Republican groups are finally going up on the air against Donald Trump, Benjy Sarlin writes. But is the end game to defeat him or to fend off a Cruz nomination?
A newly-formed superPAC (run by Katie Packer) is up with a seven-figure ad buy in Iowa questioning "How much do we really know about Donald Trump?"
He's suggested he could skip this week's FOX News debate over Megyn Kelly's participation.