Congress’s approval rating is abysmal. No news there. But it’s important to understand why.

According to a Gallup poll released Wednesday, the reason most Americans disapprove of Congress isn’t because of a specific policy or bad ethical behavior but because of inaction and partisan gridlock. Americans believe that Congress is broken.

And there is no need for any banal stretch for a false equivalency to explain why that would be. The reason Congress doesn’t work is because Republican lawmakers have ceased to believe that it should. For too many of them, compromise has become synonymous with collusion. They would rather resist than work. So the wheels of government are screeching to a halt. Obstruction and bluster have replaced solutions and courage.

As the former Clinton labor secretary Robert Reich wrote last week:“Conservative Republicans in our nation’s capital have managed to accomplish something they only dreamed of when Tea Partiers streamed into Congress at the start of 2011: They’ve basically shut Congress down. Their refusal to compromise is working just as they hoped: No jobs agenda. No budget. No grand bargain on the deficit. No background checks on guns. Nothing on climate change. No tax reform. No hike in the minimum wage. Nothing so far on immigration reform.”On that last point at least, Congress has a chance at redemption. It may be the best chance this year — and possibly the last during the Obama administration.

But the Republican caucus is deeply torn about how to deal with — and discuss — comprehensive immigration reform. Acerbic dissension among conservatives is doing damage to the Republican brand even as the legislation holds the promise of lifting the Congressional brand.

This could mean that whatever comes of the bill — pass or fail — Republicans could in fact get the worst of both worlds. If it passes, Republicans are not likely to be credited with the victory, and if it fails they will most likely be seen as responsible for the failure.

They have only themselves to blame.

Last week, the Republican-led House of Representatives voted to defund the Deferred Action for Childhood Arrivals programs, essentially voting to deport more Dreamers. (Only six Republicans voted against defunding the program; only three Democrats voted for it.) After the vote, the Hispanic Caucus tweeted: “House Republicans just voted to treat Dreamers and undocumented spouses of servicemembers in the same way as violent criminals.”When the Senate tried Tuesday to bring the “gang of eight” ‘s immigration bill to the floor, all 15 senators who voted to filibuster the law were Republicans.

The optics on this bill don’t look good. And things get worse online, where many Republican commentators have dubbed the bill “Shamnesty.” Opponents of the measure accuse Republicans who are for it of being apostates to the conservative cause, concerned more about presidential politics than principle and defending the Constitution.

There may be some measure of truth in these charges. Most political positions have a degree of ambiguity, a mix of genuine concern and raw cynicism.

For instance, while Hispanics make up about 16 percent of the population as a whole, three of the four Republican members of the Senate’s “gang of eight” — John McCain, Jeff Flake and Marco Rubio — are from states where the Hispanic population is more than 22 percent.

The one exception is Lindsey Graham of South Carolina, whose Hispanic population is only about 5 percent, but he has his own particular problems.

First, as the Augusta Chronicle pointed out in 2011:“South Carolina’s population grew by 15.3 percent during the past 10 years, but its Hispanic population grew 148 percent.” Those are the kinds of numbers that can make a politician sit up and take notice.

And Graham’s current electoral math seems tougher than his last time out.

According to an April Winthrop University poll: “United States Senator Lindsey Graham, who is up for re-election in 2014, received a 44 percent approval rating among South Carolina registered voters, but his approval rating has dropped from 71.6 percent to 57.5 percent among Republicans and those independents who lean toward the G.O.P. compared to the February poll. This drop corresponds to the entry of two vocal challengers, and discussion of a third, into the primary race against him.”Furthermore, McCain ran for president in 2008 and lost, in part because he lost the Hispanic vote 2-to-1 to Barack Obama. And Marco Rubio is almost certainly making a run for the White House in 2016.

Whatever these senators’ motives, it’s clear that the Hispanic population is growing in many of their Southern, stronghold states, and it’s becoming increasingly hard to imagine a presidential victory without substantial Hispanic support.

But it’s becoming just as apparent that far-right conservatives see immigration legislation that allows a path to citizenship for illegal immigrants as a suicidal mission.

The problem is that their overwrought opposition — which may well be futile — may prove as damaging to their party as to the legislation itself.