And Bush is right: It can take a lot of flexibility for a politician to keep up with it all. He would know, after all.
Here's how many of the top 2016 candidates have shifted on immigration.
Let's start with Jeb Bush himself
What he said then: Bush has unapologetically supported immigration reform in recent years. In 2004 as Florida governor, the Republican supported a controversial bill for illegal immigrants to get driver's licenses. But he has a long, complicated relationship with the notion of supporting a pathway to citizenship, a feature of most major efforts to overhaul the immigration system and a must-have for immigrant groups.
What he said then: A few things, actually. In the summer of 2012, Bush told ABC's Charlie Rose he does support a method for immigrants who are in the country illegally to become citizens, fact-checking site Politifact reported in 2013.
"You have to deal with this issue. You can’t ignore it. And so, either a path to citizenship, which I would support and that does put me probably out of the mainstream of most conservatives, or a path to legalization, a path to residency of some kind."
But later that year, Bush appeared to say the total opposite in his book, "Immigration Wars," which was published March 5, 2013.
Permanent residency in this context, however, should not lead to citizenship. It is absolutely vital to the integrity of our immigration system that actions have consequences — in this case, that those who violated the laws can remain but cannot obtain the cherished fruits of citizenship. ... A grant of citizenship is an undeserving reward for conduct that we cannot afford to encourage.
What he's saying now: Bush no longer talks up a path to citizenship. He says he does want some kind of "legal status" for undocumented immigrants.
"We need to enforce the laws of our country for sure -- enforce the border. There's a lot of things we need to do, but a practical solution of getting to fixing the legal system is also allowing for a path to legalized status -- not necessarily citizenship," he said May 12 on Fox's "The Kelly File"
Flip-flop rating: A full-on somersault
As governor of Texas, Perry (R) signed a law allowing undocumented immigrants to apply for in-state tuition.
What he's said: People who oppose that law "don't have a heart," Perry said in a 2011 Fox News presidential debate.
What he's saying now: "That was a really bad choice of words," Perry told the Wall Street Journal in his final weeks as governor last January. But he said in that same interview that young immigrants brought to the country illegally "ended up in this state in most cases by no action of their own," appearing to echo President Obama's argument about why so-called dreamers should be allowed to stay in the country.
Flip-flop rating: A skip away, then a skip back.
The Republican former Pennsylvania senator and now-two-time presidential candidate has always been a hardliner on immigration, opposing a path to citizenship of any form, as PBS NewsHour noted .
What he's said: Santorum agreed with previous Republican nominee Mitt Romney that immigrants in the country illegally should "self-deport."
"The bottom line is we need to enforce the laws in this country," Santorum said in a 2012 Republican debate.
What he's saying now: Enforcing current laws is apparently not enough. The government should also restrict the flow of legal immigrants into the country.
"We see wages depressed, we see median income going down, and I think legal immigration is a part of that puzzle," he told MSNBC in a Jan. 19 interview.
Flip-flop rating: What's the opposite of a back flip? A front tuck?
We can't mention immigration reform shifts without touching on Florida Sen. Marco Rubio (R). He was one of the champions for immigration reform -- including a path to citizenship -- in 2013. When a bill he helped draft passed the Senate in June of that year, senators patted him on the back and said "Good job," the New York Times's Ashley Parker reported.
What he said then: "Like every sovereign nation on this planet, we have a right to control who comes in, but unlike other countries we are not afraid of people coming in here from other places," Rubio said in a speech on the Senate floor the day it passed, June 27, 2013.
What he's saying now: Rubio took a lot of heat from his fellow Republicans for his position. Nearly two years later, he now says he was wrong to focus on a path to citizenship before first ensuring the border is secure. In fact, he's learned a lesson from the whole experience.
"What I've learned is you can't even have a conversation about that until people believe and know, not just believe but it's proven to them, that future illegal immigration will be controlled," he said in February at the Conservative Political Action Conference.
In May, Rubio's team expanded on his stance and told Politico this:
Florida Sen. Marco Rubio, meanwhile, has said most recently has said he supports giving law-abiding undocumented immigrants a chance to apply for "permanent residency" in the U.S. if they pay a fine, speak English, go through background checks, and spend over a decade here under a nonpermanent work visa.
Flip-flop rating: Rubio is all over the place.
The Republican Wisconsin governor openly admits his "view has changed" on the subject. Over the past two years, he's done a 180 and then some (a 200?).
What he said then: In 2013, Walker said it "makes sense" to give a path to citizenship to undocumented workers already in America.
"We just have a broken system. And to me, if somebody wants to come in and live the American dream and work hard … we should have a system that works and let’s people in," he told Politico on Feb. 22, 2013.
What he's saying now: "I don't believe in amnesty," Walker said in March, as documented by The Washington Post's Jenna Johnson. Later that month, after New Hampshire business leaders told the Post's Robert Costa that Walker said he'd support some sort of pathway to citizenship, Walker's spokesperson clamped down on that theory, telling Costa that Walker "does not support citizenship for illegal immigrants, and this storyline is false."
Flip-flop rating: A double triple back flip.
And before you start typing your e-mail asking, "What about Hillary Clinton?" we'll ask: What about her? Here's her documented shift on immigration:
"The vast majority of the people who are here, we will give you a path to legalization if you meet the following conditions: pay a fine because you entered illegally, be willing to pay back taxes over time, try to learn English -- and we have to help you do that because we've cut back on so many of our services -- and then you wait in line."
What she's saying now: A President Clinton would use her executive power to allow even more immigrants in the country illegally to get work permits and avoid deportation, while "fighting for comprehensive immigration reform" in Congress, she told a group of "dreamers" May 6 in Las Vegas.
Flip-flop rating: Kinda like Santorum, she's tumbling even closer to her party's base. We'll call it a front tuck.