U.S. Sen. Marco Rubio (R-Fla.) (Alex Wong/Getty Images) U.S. Sen. Marco Rubio (R-Fla.) (Alex Wong/Getty Images)

Increasingly, Sen. Marco Rubio (R-Fla.) sounds like a right-wing crank, not the freshman once thought to be the future of the party. His office now releases hyperbolic, inaccurate statements that sound as if they’ve come off the presses at Heritage Action. Rubio himself sounds like a faint echo of Jim DeMint. Yesterday, on Mike Huckabee’s radio show, he proclaimed, “To walk away from the already-agreed-upon reductions in spending which were so difficult to achieve, I think, opens the floodgates that really threaten to put us right back in these spending habits, and really we’re going to continue to have a government that spends more money than it takes in.” Of course, the budget deal does no such thing; it increases the cuts over 10 years. Budget chairman Rep. Paul Ryan rapped Rubio’s theatrics, saying, “Read the deal and get back to me. People are going to do what they need to do. In the  minority, you don’t have the burden of governing, of getting things done.” (The problem for Rubio is that he isn’t satisfied with being a freshman in the minority; he aspires to national leadership.)

Even worse, in Rubio’s apparent obsession with tiny amounts of discretionary spending the junior Florida senator repudiates his long-standing priority, namely national security. He says things such as, “I think we could have created more flexibility for the military to spend the money that it has. I think we could have looked for ways to perhaps replace the sequester on the military with some other cuts somewhere else because I think national security is important.” But it isn’t important enough to actually vote to restore funding.

His statement and announced opposition went down poorly with long-time hawkish allies already disenchanted with his refusal to back military action against Syria for its crossing the “red line.” Gary Schmitt of the American Enterprise had a response typical of those who seethed over Rubio’s antics. He told me, “Statesmanship requires more than making ‘slippery slope’ arguments, and it certainly requires a willingness to make the best of a bad situation, especially when the failure to do so puts the country’s national security at risk.”

Rubio’s position is being roundly rebutted by conservative hawks like Thomas Donnelly and Roger Zakheim. (“The Ryan-Murray deal may represent a small amount in dollars, but it’s an opportunity to get the narrative back on track for next year’s elections and particularly for the 2016 presidential contest. It’s a chance to begin strengthening our national defense, and to begin to remind ourselves that providing for the common defense is the first and fundamental job of our national government.”) And the former ambassador to the United Nations John Bolton chastised the refusal to look at political realities. He e-mailed, “I don’t think it’s a great deal, but it’s a step in the right direction. The real answer always lies in elections, If we had majorities in both houses of Congress, we’d have an even better deal. And if we had plus the Presidency, even more so.” But Rubio’s refusal to recognize those realities suggests he’d rather play in the tea party playground than operate in the real world.

Rubio’s decision runs counter to the views of the organization his top foreign policy advisor Jamie Fly once headed. Coming on the heels of a foreign trip meant to bolster Rubio’s foreign policy credentials, his rhetoric and announced opposition to the budget suggest one of several things is going on:

1. He is petrified of the hard right after championing immigration reform and now refuses to cross the hard right on any matter. This requires him to adopt inane positions (e.g. backing the shutdown) and contradict his long-espoused views (internationalism, strong on defense). He incorrectly thinks he can get back in the good graces of the far right without alienating mainstream conservatives.

2. He actually is a far-right tea partyer in the mold of Jim DeMint. He occasionally gives a good speech on human rights or immigration, but he operates in a world of political fantasy, as do the other members of the shutdown squad.

3.  He knows all too well he’s hurting himself with conservative hawks, but he’s made a conscious decision to migrate away from an internationalist foreign policy, imaging it is now out of fashion with voters. He talks a good game, but that’s not matched by actions.

Of course, it may be some combination of all these that drives his erratic behavior these days. It is hard to imagine his advisers designed this behavior; they certainly must know that Rubio has confused allies, lost his “brand” and reduced the likelihood of success in a presidential run. Ironically, Rubio’s brand meltdown comes at the very time the tea party is losing steam. Rubio is, in essence, pandering to (or embracing the talking points of) a group seriously declining in popularity and increasingly characterized by cartoonish candidates. His decline as a serious leader is a sad development for the conservative movement and for the country.

UPDATE: Another respected conservative voice, Peter Wehner, weighs in, making the salient point Rubio “originally voted against the sequester, in part, he said, because it cut defense too much. ‘Defense funding should be driven by our national security needs, not by arbitrary fiscal arithmetic,’ he said in a joint statement with other senators. ‘We cannot responsibly allow across-the-board, draconian defense cuts to go forward at the expense of our national security.’ Now he’s criticizing a budget deal that would increase spending on defense while also slightly cutting the deficit, arguing that we shouldn’t give up the sequestration deal he initially opposed. And he’s the one complaining about the lack of ‘long-term thinking.'” It is well worth reading in full.