In the past, Joe Scarborough hasn't exactly hidden his disdain for Marco Rubio, saying he reminds him of an eager student government candidate and questioning his integrity. But things have now escalated to open warfare between the two. 

Scarborough, responding to an ad in which Rubio speaks of feeling "out of place in our own country," tweeted an attack accusing Rubio of playing a "crass, offensive, nativist" [read xenophobic/borderline racist] card. Rubio has fired back, putting out a fundraising message in which he slams Scarborough as an "elitist."

James Warren at Poynter MediaWire noted that last week, Bernie Sanders picked up the endorsement of the Communications Workers of America, a 600,000-member union that includes 26,000 members of the NewsGuild – representing “journalists at The New York Times, The Washington Post, The Wall Street Journal, St. Louis Post-Dispatch, The Boston Globe, San Jose Mercury News, digital start-up Truthout and the digital operations at many, but not all, big print publications, such as Philly.com.”

Warren protested: “For those who believe nearly all journalists not on the Fox News payroll must be knee-jerk lefties pushing an agenda, be informed that the Guild heeded a nearly reflexive tradition and abstained in its parent's endorsement vote.”

Though Steve Benen, who's also the primary blogger for the MSNBC program's website, is a true-blue liberal, he thinks highly of the foreign-policy chops of some recent Republicans. In a Thursday post, Benen wrote that GOPers such as Richard Lugar and Brent Scowcroft were “learned” and “approached international affairs with [a] degree of maturity.”

That was then; this is now. Benen touched on, among other things, Ted Cruz’s pledge to “carpet bomb” ISIS and Marco Rubio’s remark that the 2003 invasion of Iraq was “not a mistake” to build a case that today’s Republican party “approaches foreign policy…with all the maturity of a Saturday-morning cartoon…The national GOP candidates are speaking to (and for) a party that has no patience for substantive details, historical lessons, nuance, or diplomacy.”

CNN's New Day on Monday actually spotlighted Hillary Clinton's false claim on Saturday that ISIS is "showing videos of Donald Trump insulting Islam and Muslims in order to recruit more radical jihadists." Chris Cuomo asserted that "it's very hard to translate it any other way...we can't find the videos." When liberal pundit Errol Louis speculated that Clinton's campaign would "migrate towards some kind of clarification," Cuomo replied, "How could you clarify it? How is it anything but wrong?"

It's rare when a politician says something surprising, or doesn't succumb to a feel-good suggestion. Which made Rick Santorum's response to Joe Scarborough this morning doubly remarkable.

On today's Morning Joe, Scarborough had teed Santorum up to agree with his suggestion that we need to "reach out aggressively to let Muslim Americans know that they are every bit a part of the American dream as you or me." But Santorum turned the tables, saying "I would ask that in reverse: what are they going to do to reach out to make sure they are confronting --" Scarborough broke in: "no, no, no. I don't think so." But a composed Santorum went on to calmly make his case, calling out in particular CAIR for "continuing to apologize for the radicals."