For much of 2015, Marco Rubio preferred to focus his attention on President Obama and Hillary Clinton, leaving intra-party criticisms to his rivals. But as Ted Cruz starts to appear more formidable, the Florida senator is suddenly investing quite a bit more time in trying to raise doubts about his Texas rival.

That’s not surprising. What is surprising is Rubio’s preferred line of attack. Politico reported the other day: Politico

[Rubio] told donors that he intended to keep up his criticisms of rival Ted Cruz, with whom he has been sparring recently over national security and immigration. Rubio, who has cast Cruz as not quite as ardent a foe of legalization as he says, said he would continue to portray the Texas senator as politically inconsistent.

BuzzFeed added that Rubio appeared on a New Hampshire radio show last week, arguing that Cruz “has shown throughout his career that he’s been calculating in his position on some issues,” including immigration. The Texas Republican, Rubio added, “has been tempered by the political winds.”

C ruz and his campaign team are obviously capable of defending themselves, but what’s so striking about Rubio’s talking points is the breathtaking failure of self-awareness.

The Florida senator wants to focus on “consistency” and the propensity for being “calculating,” especially in the area of immigration? For some GOP presidential candidates, this might seem like a potent line of attack against Cruz – but Rubio isn’t one of them.

We are, after all, talking about a senator who co-authored the Gang of Eight immigration-reform package – which much of the Republican base now condemns as “amnesty” – championed by President Obama and congressional Democrats. Rubio not only voted for the bill, he also rejected GOP amendments intended to move the proposal to the right.

Rubio then betrayed his allies and announced he’d abandoned the comprehensive legislation he helped write, shifting with the winds in the hopes of placating the Republican base and helping his 2016 campaign.

The editorial board of the Washington Post recently asked , “Will Sen. Marco Rubio (R-Fla.) ever stop atoning for his apostasy in having supported an overhaul of America’s broken immigration system? Or is he so politically pliable and ideologically biddable that he will say anything, and take any stance, to shield himself from the ugly nativism Donald Trump has tapped among Republican primary voters?”

This is the guy who wants to talk about “consistency”? After Rubio abandoned his own signature cause to placate his party’s base, he decided to accuse others of shifting with “the political winds”?

Seriously?

Vox recently pondered why Rubio hasn’t received more support from the Republican Party’s establishment. “If you stop looking at him through liberal-tinted lenses,” the piece explained , “you see a politician whose brief but tumultuous record in national politics is marked by fairly erratic behavior…. Rubio has backstabbed a lot of people over the past five years, none of it in pursuit of any especially clear factional goal.”