WASHINGTON (AP) — Often elusive, the political center is holding steady in the Senate as a coalition of Democratic and Republican senators brushes off critics to push the $1 trillion infrastructure package toward final passage.

On the left, the Democrats have withstood the complaints of liberals who say the proposal falls short of what’s needed to provide a down payment on one of President Joe Biden’s top priorities.

From the right, the Republicans are largely ignoring the criticism from their most conservative and far-flung voices, including a barrage of name-calling from former President Donald Trump as he tries to derail the package.

All told, some 70 senators appear poised to carry the bipartisan infrastructure bill to passage, a potentially robust tally of lawmakers eager to tap the billions in new spending it will unleash for public works projects back home.

“This is something that brings this country together,” said Sen. Rob Portman, R-Ohio, a lead negotiator. “We need the investment, let’s be honest.”

Senators hoisted the package over another hurdle late Sunday, easily clearing a remaining 60-vote threshold on a vote of 68-29, despite a few holdouts trying to run out the clock on debate and drag final passage to Tuesday. The measure would then go to the House.

“A very handsome, overwhelming vote,” said Senate Majority Leader Chuck Schumer, D-N.Y.

The rare bipartisan momentum reflects a political power center that has sprung from the middle of the aisle in the narrowly split Congress. For weeks, senators have negotiated and shaped the package, overcoming partisan gridlock for a compromise with the Biden White House. A bipartisan group of House lawmakers has pledged its own support.

Backed by Biden and a sizable coalition of business, farm, labor and public interest groups, the package is one of the biggest investments of its kind in years. The Infrastructure Investment and Jobs Act seeks to inject nearly $550 billion in new spending on roads, bridges, broadband internet, water pipes and other public works systems undergirding the nation. Some 20 Republican senators are poised to join Democrats in supporting support it.

“Look at the players,” said Sen. Richard Burr, R-N.C. “These are not the fringes of both parties.”

Once voting wraps up, senators immediately will turn to the budget outline for a $3.5 trillion package of child care, elder care and other programs that is a much more partisan undertaking and expected to draw only Democratic support.

Despite the momentum, action ground to a halt over the weekend when Sen. Bill Hagerty, a Tennessee Republican allied with Trump, refused to speed up the process.

Hagerty, who had been Trump's ambassador to Japan, argued for taking as much time as needed for debate and amendments, in part because he wants to slow the march toward Biden's $3.5 trillion bill aimed at so-called soft infrastructure.

Trump called Hagerty on Sunday morning, said a person familiar with the call who requested anonymity to discuss it. Hagerty said later Sunday he was trying to prevent a “socialist debt bomb” of new government spending.

Senate Republican leader Mitch McConnell, R-Ky., has so far allowed the bill to progress, calling the bill “a compromise.”

Senators have spent the past week processing nearly two dozen amendments to the 2,700-page package, but so far none has substantially changed its framework.

More amendments have been offered on cryptocurrency, defense-related infrastructure and to allow states to repurpose a portion of their untapped federal COVID-19 relief aid for infrastructure. But it's unclear if they will be considered for votes.

Senators have found much to like in the bill, even though it does not fully satisfy liberals, who view it as too small, or conservatives, who find it too large.

An analysis of the bill from the Congressional Budget Office drew concerns, particularly from Republicans after concluding the legislation would increase deficits by about $256 billion over the next decade.

Unlike Biden's bigger $3.5 trillion package, which would be paid for by higher tax rates for corporations and the wealthy, the bipartisan package is funded by repurposing other money, and other spending cuts and revenue streams. The bill’s backers argued that the budget office was unable to take into account certain revenue streams — including from future economic growth.

The House is expected to consider both Biden infrastructure packages when it returns from recess in September.