For months, out of respect for the process and his friends in the crowded GOP field, the Republican Party's 2012 nominee has told friends and the candidates who have courted him that he is happy to share stories and advice but is not inclined to endorse, at least not so early on.
But Iowa is, at a minimum, stirring a fresh assessment.
Romney shares the view, associates say, that if Donald Trump loses New Hampshire, his campaign would likely collapse, suffering back-to-back defeats in the first two contests that would strip the billionaire businessman of his "winning" brand.
Can Trump be beat in New Hampshire? That is the question, especially given that several "establishment," or more traditional center-right Republicans, are contesting -- along with Trump -- for the slice of the electorate that gave Romney his big 2012 win in New Hampshire.
The former Massachusetts governor now calls New Hampshire home, and he has a deep network of supporters from his 2008 and 2012 presidential campaigns.
A Romney endorsement before Tuesday's first-in-the-nation primary would no doubt be a boon for the lucky recipient.
Again, those who have discussed the question with Romney say caution is his watchword.
And as recently as the past 48 hours, Romney has told associates in at least two of the GOP campaigns that he has no plan to endorse before New Hampshire votes.
But close Romney allies do not rule out a last minute change of heart. In saying that, they acknowledge a shift in his thinking about the race post-Iowa, and these sources tell CNN that should Romney decide to drop his neutrality before Tuesday, the all-but-certain recipient of that blessing would be Marco Rubio.
CNN is told there is a fresh Rubio effort to win Romney's endorsement based on his third place showing in Iowa. The Florida senator's team makes the case that now is the time to coalesce around Rubio as the strongest alternative to Trump and Texas Sen. Ted Cruz.
In one sign of where Romney allies are leaning, Susan Duprey, who was Ann Romney's chief of staff during the 2012 presidential campaign, announced her endorsement of Rubio on Tuesday
Some, but hardly all, of the friends and GOP strategists with whom Romney discusses big political moves are described as believing it is at least worth a new conversation about whether a Rubio endorsement before Tuesday makes sense.
Romney, according to sources close to the former Massachusetts governor, has a trademark reaction to such talk: Is there data to support the argument that Rubio is in play to defeat Trump in New Hampshire?
In short: Is there evidence to persuade Romney it is worth getting involved now -- a decision that would put his personal prestige on the line and disappoint his other friends in the field?
Indeed, Rubio's team isn't the only campaign to have begun its outreach to Romney. Associates of John Kasich and Chris Christie have lobbied Romney to support their respective candidates in recent days. The signal they are getting from Romney allies is that he is unlikely to endorse before the New Hampshire primary.
A person with knowledge of Romney's thinking said while an endorsement was unlikely, that could certainly change.
Indeed, if he did jump off the sidelines, he would almost certainly anger a number of his close allies.
Romney was said to be traveling to Utah on Wednesday. Associates suggested conversations about whether to abandon his neutrality in the race might come a bit later in the week, when there also likely will be polling and other data available on how much, if at all, the Iowa results have changed the state of the race in New Hampshire.
Romney wary of Cruz, Trump
For months, Romney has quietly been involved in conversations among senior Republican leaders about the prospect of either Cruz or Trump winning the Republican nomination. The 2012 nominee is described as in "total agreement" with other party establishment figures -- including his 2012 running mate and now House Speaker Paul Ryan -- that GOP candidates for congressional and other races would likely suffer if Cruz or Trump lead the ticket.
Throughout this period, Romney has both been urged to run again -- something he has resisted -- or to take a more active role by throwing his weight, and his fundraising network, behind one of the GOP candidates.
He has resisted, however, out of respect for the process he endured twice and because he has several friends in the race that he believes should have an equal chance to make their case.
Just in recent weeks, friends say they know Romney has discussed the race directly with Kasich and Christie, not to mention some of their top backers. He has a warm relationship with Rubio, and former Romney staffers are sprinkled throughout the Republican campaigns. He recently raised eyebrows with critical remarks about the campaign of former Florida Gov. Jeb Bush. Romney and Bush are not close, but Romney deeply admires former President George H. W. Bush and is sensitive to his status as a GOP elder.
A counterbalance to his trademark caution could be his firsthand knowledge of how a big endorsement can help: One day after the 2012 Iowa caucuses, Romney flew to New Hampshire and was endorsed by his 2008 rival -- and the ultimate GOP nominee that cycle -- Arizona Sen. John McCain. Romney narrowly lost Iowa to Rick Santorum before winning New Hampshire.