Battered by critics and dire opinion polls, President Joe Biden signs into law the biggest US infrastructure revamp in more than half a century at a rare bipartisan celebration in the White House on Monday. The $1.2 trillion package will fix bridges and roads, as well as expand broadband internet across the United States, in the most significant government investment of the kind since the creation of the national highways network in the 1950s. Infrastructure spending is popular, but the goal eluded Biden’s predecessor Donald Trump for four years, turning his administration’s frequent promises that “infrastructure week” was imminent into a running joke. Even now, Biden had to fight for months to get his squabbling Democratic party to vote, risking a humiliating failure. Democrats only narrowly control a bitterly divided Congress, but in an exceptionally scarce moment of bipartisan cooperation they were ultimately joined by a significant number of Republicans in the Senate and a symbolic handful in the House. Biden will hail that breakthrough at a signing event on the South Lawn on Monday, where members of both parties are invited. However, the feelgood moment may be fleeting. Biden’s ratings are in a downward spiral, with the latest Washington Post-ABC poll showing just 41 percent approving. Most worrying for the White House, support is ebbing away not just among the crucial independent voters but his own Democratic base. Neither are the bulk of Biden’s Republican opponents calling a truce to join in with the bipartisan infrastructure messaging at the White House. Trump, who is widely expected to seek to return to the White House in the 2024 election, has savaged the 13 Republicans in the House of Representatives who voted alongside the Democrats. He says Republicans who crossed the aisle should be “ashamed” and are not real Republicans. Hard-right Republican Representative Marjorie Taylor Greene, a vocal Trump booster, called them “traitors.” She tweeted out office phone numbers of the 13 fellow Republicans, some of whom reported getting torrents of violent abuse. The pressure is also on the Senate, where Republican leader Mitch McConnell, who voted for the bill, is among those keeping away from the South Lawn celebration. The signing party for Biden, who has a video-link summit with China’s President Xi Jinping set for later on Monday, is just the start of what he hopes will be a jolt for his stumbling administration. Still pending is a $1.75 trillion package for childcare, education and other social spending that Biden says amounts to a historic effort to redress social inequalities. Again, internal party divisions are holding that up. With Republicans almost certain to make gains in midterm congressional elections in just under a year, Biden’s already tenuous political momentum faces ever-growing headwinds. But after a first 10 months in power dominated by fighting Covid-19 and congressional wrangling, Biden hopes the successful infrastructure package will show that he is getting things done. Trips to New Hampshire and Detroit for speeches pitching the deal are planned this Tuesday and Wednesday.