While Sen. Rand Paul (R-Ky.) has dropped out of the Republican presidential race, he will not be endorsing any other particular candidate as the primaries crawl on, said Paul's campaign strategist Doug Stafford in a telephone press conference with Paul's top campaign staff this morning.

Paul does, though, intend to endorse whoever the Republican Party eventually settles on.

That's something his father Ron didn't do, and to at least a small extent that difference in political styles and attitudes may have kept big portions of Ron's support from surrounding Rand, in either giving or polling. I asked Stafford what the Rand campaign thought might have gone wrong with sustaining the perceived "Ron Paul movement."

Stafford was sure that the "Ron Paul movement does exist" but couldn't say precisely why Rand didn't seem to fully re-ignite it. "Voters shift from time time and what's most important to them is hard to capture" but he did see that there were many hundreds of kids still volunteering eagerly for Rand.

Most importantly, Stafford is sure that the issues Rand brought to the fore are still those that should energize anyone who was really into the Ron Paul thing. While "there are many issues that decide how people are going to vote, some within a candidate's control and some not" he reiterated what Rand has said: that the liberty movement is "definitely alive, marching on, and Rand will continue to be its voice in the Senate."

Stafford admits even Bernie Sanders might have had some appeal to the old Ron Paul coalition, especially if they were only/mostly in it for the foreign policy, and that "we saw for ourselves, sometimes [students] seem to be attracted to a candidate who spoke their minds directly, who seemed not quite the normal politician."

But he admits, when asked if Cruz might have captured some of the elusive "Ron Paul vote," that "I don't know if anyone knows where people went. It's hard to tell. Someone might have voted for Ron and went somewhere else, to others in the Republican Party or even to another party if they were purely foreign policy supporters." That said, Stafford is confident that "as we talked to liberty voters across Iowa, it is clear to us Rand was standing up for their issues."

Asked about their prediction of 10,000 student caucusers for Rand in Iowa after fewer than 9,000 total votes went to him, well, "we came short in the number of folks who came out, which is not unheard of in trying to do things with organizing students" and other campaigns were fighting for same votes so "we were not operating in a vacuum" but still think the student efforts there "lit a fire of ideas" in thousands of kids and was good preparation for "a future fight for liberty."

Chip Englander, Paul's campaign manager, thinks that even their 5th place showing proves their organization paid off, beating "every single governor" in the race including ones who spent millions of tens of millions in advertising. But "macro messaging things" that he did not specify were "beyond their control, and that happens in political campaigns.

Why did Rand Paul quit? Mostly, he realized there was little chance of winning. "We think he finished well for Iowa…but not well enough to seem like he had a chance at the nomination." Stafford stressed the good the campaign did for the ideas of liberty in general, how especially in the debates Paul was a passionate and forceful voice for his issues, from foreign policy to the Fourth Amendment to criminal justice reform. If not for Paul, in no case would his unique perspectives on those matters have been aired.

Paul wants to return to concentrating on being a "leader of an ideological movement and a leader in the Senate" and the trajectory of the race post-Iowa seemed beyond his ability to shape.

Even in immediately forthcoming New Hampshire, which most people assumed Paul would try to fight through, while the campaign believed their ground game was solid, the media attention and money that the leading candidates had, plus the blow of being blocked from the debate prior to the primary, made them decide that "ground game couldn't overcome numerous obstacles in our path a little larger than that." Chip Englander also alluded as above to not-precisely-specified "macro message" issues, which might mean, though no one said it this bluntly, that Paul's message just isn't what a lot of Republican voters want to hear right now.

Of course, Trump changed everything, and as Stafford said "took all the oxygen out of the room" and commanded the discussion. He admitted it was "very difficult to have what you believe is a stronger message and a stronger candidate but you can't break through because celebrity became the largest thing." Paul faced a "brand new environment, for most involved in presidential politics we've never seen anything like it" and it hobbled Paul's ability to take flight "in a critical time of the race."

Stafford also acknowledged that the seeming rise of ISIS and the California terror attacks may have at least for a while shifted any possible GOP attraction to Paul's more measured foreign policy. While Stafford believes that hawkishness is "not an issue the Republican Party is fully on one side of or the other," that it is likely current events affected the ebb of public opinion in this "time of extreme events" that might have made Paul's calmer approach less appealing.

In a separate email, Steve Grubbs, who ran the Iowa operation for the campaign, said that "Senator Paul is very practical. With limited financial resources and the unlikely potential of making the debate stage this week, he chose to make the decision to refocus his time and efforts on his senate campaign. He believes in doing his job as senator which also limited his opportunity to campaign in New Hampshire this week."

Stafford in today's call also stressed that Paul was in D.C., on the Senate floor, doing his job, and had maintained a 95 percent voting record while running for president. This is something his people hope and assume will help ensure that his Kentucky voters have no interest in firing him from that job, the race for which will take up Paul's campaigning time for the rest of 2016.

Chris LaCivita with the campaign insists that Paul will keep his presidential issues alive in the Senate race and that Kentucky's Democrats are on the ropes this year and worried more about their state positioning than able to meaningfully challenge Rand for the Senate seat. The Paul campaign continues to insist the shift from primary to caucus for Kentucky, which the campaign helped finance and was intended to allow Rand to be on ballot for both president and Senate, is still a good idea for the state as it moves them further up in time when their vote might still matter to the outcome.

From the SuperPAC world supporting Paul, Edward Crane, co-founder of the Cato Institute and chief of PurplePAC (which ran a TV ad for Rand in Iowa in the week prior), is disappointed by the whole thing. "Rand dropping out is a blow to the GOP and to the nation," Crane wrote in an email this morning.

"A plurality of Americans support market (not crony) capitalism, are socially tolerant and skeptical of the efficacy of the U.S. trying to be the world's policeman," Crane believes. "Rand should have been the candidate of that plurality but he failed to mobilize it."

How did he fail? "The summer downplaying of his libertarianism when he should have been escalating it was huge mistake. A huge lost opportunity. I have tremendous respect for what Rand tried to do—the psychological, physical and financial stress are substantial—but he is not a natural leader. He came across as someone who would rather not be there. And who can blame him?"

Ultimately, Crane is "glad to have him in the Senate." While PurplePAC still has what Crane calls "some" money, he sees it as in effect held like a bank for his donors' and supporters' needs, and later "we may play in some congressional races."