Today House Republicans will vote on a temporary measure funding the government that also defunds the Affordable Care Act, meaning we may face a destructive government shutdown. (Update: The House has passed the measure.) Meanwhile, Obamacare implementation marches forward.

The GOP gamble is premised on Obamacare’s continuing unpopularity. That is very real. But there’s also cause to think time is on Obamacare’s side — exactly as GOP opposition continues to grow ever more radicalized and determined.

A new Washington Post/ABC News poll illustrates this nicely. It finds substantial overlap between public disapproval of the law and self-professed public ignorance about it — which could change as people experience it firsthand.

The poll finds 42 percent of Americans support the law, versus 52 percent who don’t. Confusion is widespread: Only 35 percent say they “have the information” they need to understand the law, while 62 percent say they don’t. Yes, Obamacare faces stiff challenges.

But here’s an interesting wrinkle. The Post polling team tells me that among those who oppose Obamacare, only 30 percent say they understand it, while 69 percent say they don’t. But among those who support Obamacare, 45 percent understand it while 53 percent don’t.

So it’s possible as knowledge of the law grows, so could approval. Meanwhile the poll finds that despite majority opposition, only 27 percent support shutting down major parts of the government to stall implementation. And shutdown sentiment is heavily driven by Republicans. As the Fix points out, 50 percent of Republicans, and 57 percent of conservative Republicans, want a shutdown — versus barely more than one forth of Americans overall. Says the Fix: “Republicans are once again wedged between what their base wants and what the broader country wants.” Yup.

As Jonathan Cohn details in a must-read this morning, millions of Americans are going to begin experiencing the law firsthand, as follows:

…how, for the first time, people buying insurance on their own will be able to get policies regardless of pre-existing conditions; how they’ll be eligible for generous tax credits even if they are middle class; how they’ll be able to compare prices and benefits from several plans, neatly organized into metallic-sounding tiers like gold, sliver, and bronze; and how they’ll be able to do it via online marketplaces…millions of Americans are going to get access to cheaper, more secure health insurance.

If implementation goes very badly, of course, public lack of knowledge of the law could work against it. But the opposite is a very plausible possibility. Meanwhile, guerrilla resistance to the law among a radical minority continues to exert outsized control over the GOP, and there are no signs that will change in the near future.

* REPUBLICANS FRET ABOUT LOSING SHUTDOWN FIGHT: David Drucker reports that Republicans are publicly and privately very worried the President will have the upper hand in the possible government shutdown fight, and that history suggests they have good reason to worry. Note this:

“There has to be definable and winnable argument,” said David Winston, a Republican pollster who has researched this issue. “If you’re going to go down a path that could end at this location, nobody wants to hear that this is where you’re going to end up. People want you to overcome this and govern.”

Winston does polling for the House GOP leadership, so for him to be sounding the alarm suggests genuine anxiety at high levels of the GOP.

* OBAMA PRESSES FORWARD ON CARBON EMISSIONS: EPA chief Gina McCarthy will today unveil the administration’s long awaited rules imposing strict curbs carbon emissions from new power plants. Meanwhile, McCarthy will embark on a year-long “listening tour” as the administration seeks to prepare even more controversial rules on existing plants.

The moves, which will provoke intense Republican opposition and a court battle with industry, signal the administration will aggressively use executive actions to bypass a Congress paralyzed on global warming by a party populated by climate “skeptics.” Now — what about Keystone?

 * TED CRUZ’S SCAM IS FALLING APART: Byron York games out how the Senate will proceed with the House GOP bill to fund the government while defunding Obamacare, and determines conservative Senators have no options for stopping Senate Dems from stripping out defunding and sending a “clean CR” back to the House.

This confirms two things we’ve known all along: One, the defund crusade was always a scam that could never work. Two, House GOP leaders are only delaying the inevitable — they will have to choose between stiff-arming the Tea Party and taking the blame for a government shutdown.

* THE GOP BASE’S UNREALISTIC EXPECTATIONS: As Eugene Robinson notes, the trouble with Cruz’s scam, even if it’s falling apart, is that it has created a serious problem for even moderate GOP lawmakers:

Irresponsible demagogues — I mean you, Sen. Ted Cruz — have whipped the GOP base into a frenzy of unrealistic expectations. House members who balk at jumping off the cliff risk being labeled “moderate,” which is the very worst thing you can call a Republican — and the most likely thing to shorten his or her political career. The way to end this madness is by firmly saying no. If Boehner won’t do it, Obama must.

Indeed, I’d add that GOP leaders have helped create this problem by keeping alive the illusion that defunding is a real option for as long as possible, to avoid dealing with the inevitable.

* DEMS BLAST 2016 GOP HOPEFULS ON ECONOMY: With 2016 GOP contenders Rand Paul, Scott Walker, and Bobby Jindal descending on a Michigan conference this weekend, the DNC releases a new video recapping Obama’s rescue of the auto industry and its subsequent rebound, along with the panning of the auto-bailout by all those Republicans. The auto rescue remains a stark example of the most basic differences between the parties over when and how government should intervene in the economy — one that will continue to resonate politically for years.

* THE BIG STORY THIS FALL WILL BE THE GOP: Paul Krugman’s column today pushes back on all the Green Lanternites, pointing out the folly of blaming Obama for failing to compromise with a GOP that is in the grip of a base that has taken a turn into sheer insanity:

This story is all about the G.O.P. First came the southern strategy, in which the Republican elite cynically exploited racial backlash to promote economic goals, mainly low taxes for rich people and deregulation. Over time, this gradually morphed into what we might call the crazy strategy, in which the elite turned to exploiting the paranoia that has always been a factor in American politics — Hillary killed Vince Foster! Obama was born in Kenya! Death panels! — to promote the same goals…now we’re in a third stage, where the elite has lost control of the Frankenstein-like monster it created.

As I keep arguing here, the story that matters is whether the GOP can reconcile divisions over how aggressively to confront Obamacare, now that elites have lost control of the anti-Obamacare genie they unleashed.

 * AND THE QUOTE OF THE DAY, OBAMACARE DERANGEMENT EDITION: GOP Rep. Ted Yoho seems to think the crusade to defund Obamacare is on par with Civil Rights, and as such will force GOP leaders to keep up the fight:

“It only takes one with passion — look at Rosa Parks, Lech Walesa, Martin Luther King. People with passion that speak up, they’ll have people follow them because they believe the same way, and smart leadership listens to that.”

Hmmm. I’m all for passionate civic engagement, but this looks like another outbreak of those delusions of world-historical grandeur that have afflicted so many throughout the Obama era.

What else?