The Republicans debate in Houston tonight. Anxious GOP-aligned observers see the affair as a crucial test of whether Donald Trump’s rivals will confront him with the force necessary to arrest his momentum heading into Super Tuesday, at which point he may become unstoppable.

Marco Rubio has now launched a fresh attack on Trump that may foreshadow the approach the Florida Senator will take tonight or at some later point. But if anything, this new broadside may illustrate the limitations and constraints Republicans face when it comes to stopping the Trump juggernaut.

At a rally late yesterday, Rubio called out Trump by name and faulted him for being insufficiently hostile to Obamacare and insufficiently supportive of Israel. “He thinks parts of Obamacare are pretty good,” Rubio scoffed, before casting himself as the only true scourge of the law. Rubio noted that Trump “has said he’s not going to take sides on Israel versus the Palestinians because he wants to be an honest broker.” Rubio also hit Trump for being inexperienced and ignorant on foreign policy, arguing that he’d be tougher and more knowledgeable.

What’s particularly interesting here is that Rubio’s new attacks on Trump remain comfortably within the boundaries of GOP orthodoxy: Obamacare is bad, being insufficiently pro-Israel is bad, being weak on terror is bad. All of those arguments will probably have some appeal to GOP voters.

But if we’ve learned anything, it’s that Trump may be succeeding in part precisely because he’s breaking out of conventional ideological categories. Trump does not proceed from the assumption that government is the problem; government mismanaged by stupid and/or corrupt elites is the problem. He is not committed to the idea that free markets and limited government are the solution to people’s economic ills. He promises to destroy Obamacare — reflexively — but he envisions a government role of some kind in making sure everyone has health care. He pledges not to touch entitlements, breaking with the sacred Paul Ryan covenant. He does not genuflect before George W. Bush’s national security greatness; he ridicules it.

Trump combines all this with an even harder line on immigration than most GOP elites can accept, one suffused with explicitly articulated xenophobia. As Michael Brendan Dougherty has shown, this odd mixture, shaped around the basic idea that the global economic order is rigged against you, often by those piously invoking “free trade,” is Trump’s formula. Trump is appealing to GOP voters by arguing that elites are cheating and failing them by rigging the system to help illegals, multi-nationals, and China and Mexico through stupid, shady global deals. Whether this is through corruption or simple incompetence — in which various villains are simply snookering our elites — varies by the day. In Trump’s telling, the incompetence of GOP elites was also glaringly obvious in Bush’s Iraq invasion.

Rubio’s agenda is basically built around the conventional GOP argument that restraining government and unshackling the power of free markets is the answer to middle class economic woes (though he does edge towards a more proactive middle class agenda in a way that, say, Ted Cruz doesn’t). He remains committed to neoconservative foreign policy. On immigration, Rubio has, if anything, edged in Trump’s direction, mostly abandoning his commitment to legalization and promising to scrap Obama’s deportation relief for DREAMers. Rubio appears reluctant to launch a moral and substantive critique of Trump’s immigration demagoguery out of fear of offending his voters, but he can’t get to Trump’s right on immigration, either, so he can’t win there.

Thus, arguably, Rubio cannot go hard at the very things that may be enabling Trump to succeed. Rubio is largely constrained into launching thoroughly conventional Republican attacks on this thoroughly unconventional politician. Rubio has not yet explained to Trump’s voters why they should prefer conventional Republican economic and foreign policy promises and doctrines to Trump’s overarching story-line, which is that our system and our elites (including Republican ones) have been playing you suckers for decades; that he gets this; and that he will bust things up and set them right.

Now, Rubio may still prevail by attacking Trump as a phony conservative, or by attacking his volatile temperament and business dealings. Rubio may still muddle through to victory by winning enough moderates with the promise of a more youthful, dynamic, forward-looking candidacy, or by exploiting his remaining structural advantages, or through a grueling delegate fight. But if Rubio does fail to derail Trump, the constraints that limit the acceptable range of Rubio’s substantive critiques of Trumpism might end up being why.


* RUBIO MAY LAY OFF TRUMP TONIGHT: Alex Isenstadt reports on the Rubio camp’s preparations for the debate:

The Florida senator has concluded that going after Trump would accomplish little, given that the businessman’s supporters are deeply committed and unlikely to swing Rubio’s way. Inciting a confrontation with Trump onstage would create drama but wouldn’t help the senator gain voters, something he badly needs as he looks for his first primary win. Instead, Rubio’s team has decided his best bet is to focus fire on Cruz….The only way to dislodge Trump, Rubio’s advisers say, is to turn it into a two-man race – meaning that they first need to get Cruz out of the way.

In other words, Rubio is committed to his long game strategy here. But why do we assume Cruz’s supporters would go largely to Rubio?

Between now and March 14, delegates will be awarded proportionally. Starting March 15, states will be allowed to award delegates on a winner-take-all basis. On that day alone, Florida, Illinois, Missouri and Ohio, with a combined 292 delegates allocated in that way, are among the states or territories with contests.

So the key questions are: Will Trump pile up an insurmountable delegate lead in the contests before March 15th? Can Rubio beat Trump in his home state of Florida to begin to overcome a big deficit?

Priebus has begun stating in private meetings that the party has sway over its at times unwelcome front-runner because it has tools Trump will need to use to win a general election — voter data and field, digital and media operations that a nominee typically inherits from the party infrastructure. Dangling access to these resources, Priebus thinks he can help steer Trump toward partywide policy goals and away from the inflammatory rhetoric that Republican officials see as divisive and dangerous, especially outside of the primary.

Because if there’s one thing that’s obvious, it’s that Trump is easy to control and is willing to take his cues from the GOP establishment. If anything, this signals an increasing acceptance of the likelihood that Trump will be the nominee.

* HILLARY TROUNCES BERNIE AMONG HISPANIC DEMS: A new Washington Post-Univision News poll finds that Hillary Clinton is leading Bernie Sanders among Hispanic Democrats nationally by 57-28, a margin of two to one. This casts doubt on whether Sanders is making serious inroads among nonwhite voters, which he needs to do in order to offset Clinton’s advantage heading into the big, diverse contests.

However: Sanders leads Clinton among Hispanic Dems of ages 18-34 by 49-35 — a sign that Sanders’s appeal to young voters may provide him with a wedge to make at least some inroads among nonwhites.

 * HISPANICS REALLY, REALLY DON’T LIKE TRUMP: The new Post-Univision poll also finds:

Today, 8 in 10 Hispanic voters have an unfavorable view of Trump. That includes more than 7 in 10 who have a “very unfavorable” impression of him, which is more than double the percentage of any other major candidate.

Clinton beats Trump among Hispanics by 73-16. Nominating Trump is just the thing to address the GOP’s long-term demographic woes!

Trump embraces positions on economics and foreign policy anathema to most conservative politicians. He is an ardent critic of recent free-trade agreements, opposes cuts to Social Security and Medicare, has been even more vocal than many Democrats in criticizing President George W. Bush and the Iraq War, and even endorses the Democrats’ long-standing call for government negotiations with pharmaceutical companies to drive down drug costs….But unlike Democrats, Trump is a sharp critic of illegal immigration, multiculturalism and “political correctness.”

Also: Trump is a threat to conservativism because he has shown that a lot of Republican voters don’t believe free markets and limited government offer the keys to their economic salvation.

Marco Rubio’s rise to prominence

NATIONAL HARBOR, MD- MARCH 5 : Sen. Marco Rubio (FL) speaks at the Conservative Political Action Conference (CPAC) at the Gaylord National Resort & Convention Center on Saturday, March 5, 2016 in National Harbor, MD. (Photos by Amanda Voisard)