In the last Republican debate, Chris Christie said, "I'm against the recreational use of marijuana." Christie also said that if he became president, he'd enforce federal drug laws over state laws like those in Colorado where pot is now legal.
A 2014 Reason-Rupe poll showed that 83 percent of millennials opposed jailing marijuana offenders.
53 percent of Americans now support marijuana legalization. 68 percent of millennials support it. 63 percent of Republican millennials support it.
Carly Fiorina said at the same debate, "We are misleading young people when we tell them that marijuana is just like having a beer. It's not." Many experts disagree.
Still, 47 percent of millennials think beer is more damaging than marijuana compared to only 13 percent who say pot is worse, according to a 2014 Rare under-40 poll on millennial attitudes.
Jeb Bush fought against legalizing medical marijuana in his home state of Florida. His fellow Floridian Marco Rubio has expressed similar sentiments, and joins Christie in saying he'd use federal law to go after marijuana users.
These Republicans do not represent every GOP candidate's positions on marijuana and legalization. But they do represent a broad perception—particularly among millennials—that Republicans are out-of-step with younger Americans on this issue.
And this is not the only one.
When the Supreme Court ruled same-sex marriage legal nationwide in late June, Ted Cruz called it the "the darkest 24 hours in our nation's history." Bobby Jindal said it was an "all out assault" on people of faith.
An ABC News poll in April showed 60 percent of Americans support same-sex marriage. A Pew survey in June revealed that almost 3 in 4 millennials support gay marriage. The Boston Globe noted, "During the last decade, support of same-sex marriage has grown across nearly all segments of the U.S. population."
"But Pew found that a key component to this shift was the strong support of younger Americans," the Globe added.
Not all Republicans necessarily come off as hostile to same-sex marriage as Cruz or Jindal—but to millennial ears and eyes, the Republican Party as a whole does not seem particularly hospitable to those who favor marriage equality.
Young people want more tolerance on this front and many others, but Republicans continue to appear to have a tolerance deficit.
When Ben Carson said recently that no Muslim should ever become U.S. president, a Gallup poll showed that 6 in 10 Americans would support a qualified candidate who happened to be Muslim.
Gallup did not break down support for a Muslim president by age, but a 2010 Pew Research Center poll showed younger Americans were more tolerant and "open to change."
Matching some of the leading Republican candidates against Hillary Clinton—and seeing data that showed everyone from Jeb Bush to Donald Trump being walloped by the Democrat—pollster John Zogby warned in Forbes this month, "A new Zogby analytics poll of 850 adults 18-34 years old conducted on August 25 reveals that if millennials turn out to vote, the GOP faces nothing short of a catastrophic election."
The 85 million Americans who qualify as millennials will be the largest voting block in the country in the not too distant future. Zogby forecasts, "The GOP has a real problem ... millennials."
There's an ongoing shift in priorities and a widening disconnect on values between this generation, their parents and their grandparents. There's even a significant difference in how young Americans get their news — 69 percent now get it from Facebook — where they're much more likely to see different or opposing opinions on their newsfeeds than what many cable outlets or newspapers have traditionally delivered.
The country is changing. American politics is changing.
Republicans who want to win — sooner than later — are going to have to change with it.
Commentary by Jack Hunter, the editor of Rare Politics (Rare.us) and co-author of "The Tea Party Goes to Washington" with Senator Rand Paul. Follow him on Twitter @jackhunter74.