The Senate’s infrastructure bill is a bipartisan island in a sea of partisanship. President Biden and the Republican and Democratic negotiators may be heavily invested in seeing it through to the finish, but even if they are successful, it is a one-off exercise at a time when the partisan gulf continues to widen.

An infrastructure package should be the easiest of big initiatives to command support of elected officials in both parties. The need for repair and upgrading of roads and bridges and the like is evident and the political benefits to politicians — money flowing into every state — are indisputable, which is why members of both parties have talked about it for years.

In today’s climate, however, nothing is easy, and the path ahead for the infrastructure bill remains uncertain. There are philosophical differences of long-standing about how to pay for what’s needed, but they are not insurmountable if politicians are truly intent on getting something done. There are funding issues still to be resolved. There is fine print to be worked out. An attempt to start debate failed last week, though that is not indicative of the bill’s fate.

Still, as Amy Walter of the Cook Political Report recently noted, if the infrastructure package does reach Biden’s desk for signature sometime later this year, it is likely to be the last such major initiative enacted with bipartisan support to do so. Success on the package would not foreshadow a shift back to an earlier era, one with which Biden is familiar and wishes to try to re-create, even in small ways, but would simply be one moment of cross-party good will, a temporary truce in a raging war.

President Biden addressed his priorities that now face congressional approval during a CNN town hall on July 21. (Blair Guild/The Washington Post)

Everything else about the current state of politics points in the other direction, despite Biden’s professed desire to re-create the kind of climate in Congress that he remembers from his many years in the Senate. From voting rights to the president’s ambitious domestic initiatives to the hyper-charged issue of the riot at the Capitol on Jan. 6, the split between the two parties remains unbridgeable.

Nothing speaks more directly to this condition than the ongoing dispute over investigating what happened when the Capitol was overrun on Jan. 6. And nothing underscores the problem more than how House Minority Leader Kevin McCarthy (R-Calif.), his eyes clearly fixed on becoming speaker after the 2022 midterms and his loyalties highlighted by his continuing courtship of former president Donald Trump, has approached proposals to create a body to investigate fully what happened on Jan. 6 and the days and weeks ahead of it, including Trump’s role.

The normal approach for a catastrophic event like Jan. 6 would be an independent commission patterned after the body that investigated the 9/11 terrorist attacks. Hopes that Congress would create an independent commission crashed in the Senate when Republicans balked and denied supporters the 60 votes needed to make it a reality. Republicans blocked it even though the broad terms of its makeup and mandate had been negotiated by members of both parties.

The vote in the Senate was a sign that Republicans wanted nothing to do with an extended probe into what happened when a mob stormed the Capitol with the goal of preventing the certification of Biden’s electoral college victory. Republicans especially do not want an investigation that includes examining the role Trump played in helping to cause the Capitol to be overrun by his supporters. And they certainly do not want the issue of Jan. 6 clouding the debate ahead of next year’s midterm elections.

With an independent commission blocked, House Speaker Nancy Pelosi (D-Calif.) decided to go ahead with a select committee composed of House members of both parties, though she retained the power to pick a majority of the members. Among her picks was Rep. Liz Cheney (Wyo.), the Republican most outspokenly critical of Trump’s role on Jan. 6 (she later voted to impeach him) and who is now a pariah to many in the GOP.

McCarthy had the authority to appoint five members. He decided to blow up the process with the selection of Reps. Jim Jordan of Ohio and Jim Banks of Indiana, both of whom on the day the Capitol was attacked voted against certifying Biden’s election. They would have joined the committee as disrupters rather than contributors. McCarthy and Pelosi both knew that instinctively.

Pelosi then took the extraordinary step of rejecting Jordan and Banks. Perhaps that was precisely what McCarthy had hoped. The minority leader reacted by adopting an all-or-nothing posture: Take all the Republican members he had proposed or Republicans would refuse to participate in the select committee’s work. “We will run our own investigation,” he said.

Minority Leader Kevin McCarthy (R-Calif.) on July 21 said that House Republicans would conduct their own Jan. 6 investigation. (The Washington Post)

The outcome is predictable: parallel investigations that inevitably will go in different directions, reach different conclusions and speak to different parts of the electorate — the same fracturing of message and information that encompasses so much of current politics.

The committee named by Pelosi will seek to understand not only the security problems that made it possible for the Capitol to be overrun but also Trump’s role in ways that are still not fully understood, including his conversation with McCarthy on that afternoon. The Republican investigation, if the rhetoric of GOP lawmakers about what a Jan. 6 probe should encompass is any indication, will go in other directions that will dilute the Jan. 6 focus.

Republicans complain about the lack of a bipartisan investigation after having scotched the one proposal that might have produced something close to it. That is a reminder that whatever partisanship existed in the years after 9/11, and there was a considerable amount of it as the 2002 midterm elections demonstrated, conditions today are significantly worse. They are worse in large part because the Republican Party of Ronald Reagan and George H.W. Bush and George W. Bush has devolved into a cult-of-Trump political organization, held hostage by the former president and the grievances he continues to foster.

That’s the atmosphere in which the senators from both parties are operating as they try to show that bipartisanship isn’t dead. Their work continues through this weekend, aimed at reaching agreement by early next week, if possible.

They are trying to resolve the remaining issues as they try to turn concepts into legislative language. Some of the issues are large (how much money for transit, for example). Others are smaller, though not necessarily easily resolved. Staff experts have the task of working through them.

The incentive for the group of senators — and Biden — to reach agreement, beyond the practical reasons of finally funding badly needed infrastructure projects, is to show that bipartisanship can still happen, even if it is the exception rather than the rule. Failure would only add to the forces that now drive politics.