The Biden administration’s infrastructure proposal is still making its way through the congressional sausage making process but it has already been lauded as a rare victory for bipartisanship in a divided America.

Pledging to unify America after his 2020 election win, Biden and his top supporters see the roughly $1tn package not just as a chance to repair America’s tattered and torn infrastructure but also as a model for reaching across the US’s political divide and getting things done.

Some Republicans meanwhile, tout it as showing their party remains relevant in opposition and committed to doing what it can to constructively help get America back on its feet in a competitive global economy recovering from the shock of the coronavirus pandemic.

But the truth of how the bill has come to be largely supported by both sides is a little more self-interested. Already lawmakers have been pointing to aspects of the bill that help their specific constituents back in their home states.

In speeches, press releases, and public appearances these lawmakers are arguing the benefits of the roughly $1tn package as it applies to the voters back home who elected them: they are acting less in the national interest, and more out of self-interest.

The bill is not finished. Far from it. After the Senate – where debate has proceeded at a glacial pace – it must travel to the House, where the restive left wing of the Democratic party may try and add provisions. If they do, then it comes back to the Senate for another go-around. The exact timetable for when the bill will reach Joe Biden’s desk is still unclear.

Yet many lawmakers from both sides are already celebrating pieces of the legislation for their states. Those celebrations – rather than any high-minded expressions of bipartisanship – are a firm indicator of the infrastructure deal’s positive chances of becoming law, said former Senator Mark Pryor of Arkansas.

“That’s an indicator that this bill is going to pass. They’re already taking credit for it. And they don’t want to take credit for it if it goes up in flames,” Pryor said. “But they do want to take credit for the good things in here that might help their states. So what it does is it creates incentives for them to get it over the finish line.”

Senators Debbie Stabenow of Michigan and Rob Portman of Ohio, the lead Republican negotiator in the infrastructure talks, hailed a provision that provides $1bn funding to the Great Lakes region of the United States – which touches the shores of Ohio and Michigan.

“This is the single largest investment we’ve made in the Great Lakes and it’s great news! Republicans and Democrats worked together to fund the Great Lakes Restoration Initiative because we know our precious Great Lakes aren’t just a key part of our economy, they are an important part of our way of life in Michigan. This transformative investment will protect our lakes for our children and grandchildren,” Stabenow said.

In a separate press release, Senator Sherrod Brown of Ohio pointed to two bills in the infrastructure package that would repair and replace bridges in Ohio and, separately, include rules for public work projects so that those jobs are “to ensure American taxpayer dollars support American jobs”.

In a speech on the Senate floor last week Senator Jacky Rosen of Nevada noted that the bill will help expand broadband in her home state.

“It makes an unprecedented investment in building broadband infrastructure,” Rosen said.

Senator Kyrsten Sinema of Arizona, a moderate Democrat and the lead Democrat negotiator in the infrastructure talks, has sent out multiple fundraising emails on aspects of the infrastructure package.

“My colleagues and I in the United States Senate are currently considering and debating amendments to our bipartisan agreement to make a historic investment in our nation’s critical infrastructure,” Sinema wrote in the email to supporters. “It’s a huge step forward for everyday people in Arizona and across the country.”

The pitch went on to point out provisions that would replace lead pipes, improve “water infrastructure throughout the American West” and help modernize the American electrical grid.

Highlights like that underscore a situation that’s become increasingly rare in Congress but that lawmakers nevertheless love: being able to point to a new bridge or a highway and say “I brought you that, vote for me!”.

For years infrastructure has been one of those subjects both Washington Republicans and Democrats longed to see a bipartisan deal on. Broadly, both party leaders saw an incentive in being able to put a new infrastructure bill into law, because it allows them to directly please their own voters.

The calculus for Republicans remains a bit more complicated though. Former president Donald Trump has warned that Republicans participating in infrastructure negotiations are effectively “caving” to Democrats.

“This is bad legislation and politically irresponsible. The Democrats will use it to show they can get anything they want from the Republicans,” Trump said in a statement, a possible sign he might use Republican support for the bill to argue Republicans should wage primary challenges to Republican lawmakers.

“What’s interesting is a lot of these policies are very popular. In fact I think the bill will be popular in their home states,” former Senator Heidi Heitkamp of North Dakota said of the support for the infrastructure bill in Republican-leaning states. The risk for Republicans, Heitkamp added, is “if they do vote for it they could incur the wrath of the former president”.

But that may not be a deciding factor for some Republicans. Heitkamp noted that both Republican senators from North Dakota support a procedural move to advance to an infrastructure vote.

“I think the real wildcard here is the balancing act of the Republicans to figure out ‘can I vote for this? because I want to vote for it,” Heitkamp said. “But am I going to get criticized from the former president.’”