All signs are that Harry Reid is serious about his threat to exercise the nuclear option and change the Senate rules — ending the filibuster on executive nominations — by simple majority. While Republicans could still cave and acquiesce to Reid’s demand for action on a slate of nominations — allowing Dems to avoid taking the ultimate step, which they would plainly prefer — it is increasingly likely Reid will have no choice but to hit the nuke button.

If so, an epic political battle will unfold over whether the move was justified — one focused on public opinion, and even more so, on elite opinion.

The public seems to side mostly against Republicans, if a new Quinnipiac poll is any indication. It finds that a majority of voters, 51 percent, believe there is gridlock in Washington “mainly because Republicans in Congress are determined to block any President Obama initiative,” while only 35 percent believe the problem is that “Obama lacks the personal skills to convince leaders of Congress to work together.”

It’s good to see that a majority seems to subscribe, more or less, to the view that Republicans are engaged in “sabotage governing,” while barely more than a third accept the Green Lantern Theory of Presidential Power. That said, the poll does also find that a large majority, 64 percent, blame both Republicans and Democrats equally for gridlock. What’s more, 53 percent say Obama has done too little to compromise with Republicans. However, 68 percent say Republicans have done too little to compromise with Obama. So on balance, in this poll, opinion tilts against Republicans.

That said, the battle over elite opinion will be at least as important. The coverage of this standoff has largely been a he-said-she-said affair, as if it’s simply not possible that one side could in fact be more to blame for the current dysfunction in Washington than the other.

In fairness to Republicans, it is not easy to prove in a granular, numerical way that GOP obstructionism of nominations in particular is unprecedented, because there are many ways to cut and evaluate the numbers. But the broad strokes of this debate are overwhelmingly clear. It is plainly true that Republicans have effectively turned the Senate into a 60-vote, super-majority body for even routine business, in a way we haven’t seen before. It is plainly true that Republicans are obstructing Obama nominations (such as Richard Cordray as head of the Consumer Financial Protection Bureau) for the explicit purpose of preventing the agencies themselves from functioning, rather than just out of objections to the nominees themselves.

I’ll have more for you on this case later, but for now, the point is that these things matter. What’s at stake is the functioning of our democracy, and whether all of this should simply be accepted as a new normal. It shouldn’t.

If folks want to make a substantive case that all of this isn’t all that unusual or isn’t a big deal, by all means, make that case. But let’s not treat this as an argument that can’t actually be evaluated based on a set of facts, as one in which one side’s grievances can’t possibly be more legitimate than the other’s. This debate is important. And I hope folks will make a serious effort to get to the bottom of it.

* NO SUPPORT FOR GOP POSITION ON IMMIGRATION: Another key finding in the Quinnipiac poll: A majority, 54 percent, support a path to citizenship for undocumented immigrants, while only 12 percent support allowing them to stay in the U.S. without citizenship (another 28 percent support deportation). In other words, the sub-citizenship status option — the position some Republicans are adopting in order to appear willing to solve the immigration problem while not embracing citizenship — has virtually no public support at all.

Indeed, this position is only supported by 13 percent of Republicans, while the rest of them are split between citizenship and deportation. This position pleases no one.

* BROOKS CALLS ON GOP TO PASS IMMIGRATION REFORM: David Brooks has an epic column calling out pretty much every single argument conservatives have made against supporting the Senate immigration reform bill, and arguing that not supporting it could be “political suicide” for Republicans. Money quote:

Whether this bill passes or not, this country is heading toward a multiethnic future. Republicans can either shape that future in a conservative direction or, as I’ve tried to argue, they can become the receding roar of a white America that is never coming back.

Good stuff, but I’d still love to see more detailed pushback from pro-reform Republicans against the argument coming from anti-reform conservatives that the GOP faces no real demographic urgency and that killing the Senate bill is actually better politics for the party.

* GOP PRESSES FORWARD WITH DREAM-LIKE BILL: The Hill reports on the latest House GOP effort to appear willing to do something to fix our broken immigration system: “legislation to provide a path to citizenship for immigrant children who were brought to the U.S. illegally by their parents.”

Apparently this legislation would not even be as broad as the DREAM portion of the Senate bill. Still unknown: Is there anything that can get House Republicans to accept a path to citizenship for the 11 million under any circumstances?

* NEW EVIDENCE IRS TARGETED PROGRESSIVES: The IRS scandal continues to collapse:

The House Oversight committee’s top Democrat on Friday will release new evidence that the Internal Revenue Service targeted both progressive and conservative groups for extra scrutiny during the 2010 and 2012 election cycles.

There are newly discovered IRS training materials — and a Power Point presentation — that Dems say will show that IRS agents were alerted to watch for groups from both sides of the spectrum. So again: What’s Darrell Issa’s endgame here?

 * MORE ON THE “WIN MORE WHITES” THEORY OF GOP REFORM: Paul Krugman’s column today details one of the problems with this theory: The GOP agenda of downsizing the social safety net would directly impact many downscale whites the GOP needs in order to avoid changing its policies and priorities to demographically broaden its appeal. Key point: “if you look at what the modern Republican Party actually stands for in practice, it’s clearly inimical to the interests of those downscale whites the party can supposedly win back.”

* GOP STANCE ON FOOD STAMPS JEOPARDIZES “MAKEOVER”: An interesting point from Dana Milbank: The decision to get rid of the food stamp funding in the farm bill to make it acceptable to conservatives is another blow to those purported hopes of broadening the GOP’s appeal. Milbank links this to Republicans’ handling of immigration: “For the second time in two days, they had been forced to placate conservatives in their own ranks by taking a position that alienates crucial segments of the electorate.”

 * WHY THE FILIBUSTER SHOWDOWN IS LOOMING: The Post’s Paul Kane makes an important point: The showdown is in part the result of the fact that Senate leadership on both sides is under increasing pressure from new arrivals to the Senate, with conservatives demanding more confrontation and obstruction, and liberals insisting on more reform.

On the Democratic side, the potential exercise of the nuke option is clearly the result of a new influx of energetic progressives who are genuinely focused on reforming the Upper Chamber and are impatient with Senate business as usual.

* GET READY FOR EPIC BATTLE OVER FILIBUSTER: The Dem-allied Americans United for Change is out with a new web video detailing the scope of GOP obstruction of Obama nominees and legislation alike, and its consequences, labeling the Republicans the “Grand Obstruction Party.” As noted above, this is likely to be a battle over elite opinion as much as anything else, and outside groups are gearing up.

* AND THE CHART OF THE DAY, SHRINKING DEFICIT EDITION: Steve Benen offers a chart that poses an awfully good question: Why are we girding for yet another debt ceiling battle when the defict continues to fall?

What else?

Greg Sargent writes The Plum Line blog, a reported opinion blog with a liberal slant -- what you might call “opinionated reporting” from the left.