President Biden’s $2 trillion infrastructure proposal is a test of his belief that he can generate popular backing across the country as Republicans seek to block him on Capitol Hill.WASHINGTON — President Biden’s attempt to muscle through a $2 trillion plan to rebuild the country’s infrastructure — along with the tax increases to pay for it — will be a defining test of his belief that bipartisan support for his proposals can overwhelm traditional Republican objections in Congress.Instead of paring back his ambitions in an effort to limit opposition from Republicans in the Senate or appease moderate Democrats in the House, Mr. Biden and his allies on Capitol Hill are barreling ahead with unapologetically bold, expensive measures, betting that they can build bipartisanship from voters nationwide rather than from elected officials in Washington.Senator Mitch McConnell of Kentucky, the Republican leader, and other members of his party are working to brand the bill as a liberal wish list of wasteful spending and a money grab from a Democratic administration that will drag down the economy with tax hikes.But Mr. Biden is predicting that the broad appeal of wider roads, faster internet, high-speed trains, ubiquitous charging stations for electric cars, shiny new airport terminals and upgraded water pipes will undercut the expected barrage of ideological attacks that are already coming from Republican lawmakers, business groups, anti-tax activists and President Donald J. Trump.In his first cabinet meeting at the White House on Thursday, Mr. Biden directed several of his top officials to travel the country during the next several weeks to sell the benefits of the infrastructure spending. Jen Psaki, the White House press secretary, also told reporters that the president would host Democrats and Republicans in the Oval Office to discuss the plan and their ideas.“I hope and believe the American people will join this effort — Democrats, Republicans and independents,” Mr. Biden said in Pittsburgh on Wednesday as he formally announced his plan. He compared it to the popularity of the nearly $1.9 trillion pandemic relief bill that passed last month, saying, “If you live in a town with a Republican mayor, a Republican county executive or a Republican governor, ask them how many would rather get rid of the plan.”But generating sustained support for the proposal is shaping up to be a major challenge for the White House. The business lobby is preparing to wage a full-scale campaign against the tax increases in the president’s plan, with influential groups like the Business Roundtable and the U.S. Chamber of Commerce warning lawmakers against raising taxes as the United States emerges from a deep economic crisis caused by the coronavirus pandemic.But across the country, some local Republican officials are already embracing the prospect of millions of dollars in new infrastructure spending flowing into their communities, even as they are careful to express concern about new taxes.The president is betting that the broad appeal of wider roads, faster internet, high-speed trains, charging stations for electric cars, new airport terminals and upgraded water pipes will undercut the expected ideological attacks from Republicans.Todd Heisler/The New York TimesIn Fresno, Calif., Mayor Jerry Dyer said the president’s proposals, if passed into law, would allow the city to accelerate plans for a high-speed rail station linking it to job centers in the Bay Area. He said the city had struggled to electrify its fleet of buses and provide robust internet, especially to poorer communities.“These dollars are going to be welcomed in terms of repairing a lot of our infrastructure,” said Mr. Dyer, a Republican. He said he was concerned about the effects of higher taxes on businesses but added that he hoped the issue would be worked out in Washington.“There’s no question the need is there,” he said.Mayor John Giles of Mesa, Ariz., called the president’s proposal “a very good thing” for his city. With the money, Mesa could upgrade a 1970s-era airport tower, widen roads, extend broadband and expand a regional light rail network. He said he was disappointed by the Republican opposition in Congress.“It was only a few months ago that we all agreed that infrastructure was a bipartisan issue,” Mr. Giles said. “That attitude shouldn’t shift just because there’s a new administration in the White House.”But Gov. Larry Hogan of Maryland, another Republican who has called for a vast infusion of spending on infrastructure, accused Mr. Biden of using the legislation to advance $1.4 trillion in liberal programs.“It still has a lot of good things, but it also has a lot of things that have absolutely nothing to do with infrastructure,” Mr. Hogan said. “They’re like, ‘No, we just want to jam through all of our priorities.’”Mr. Biden and those closest to him understand that passage of the legislation will take place in Washington, not in Fresno or Mesa or Maryland. In announcing his plan, the president sought to cast congressional Republicans as longtime champions of infrastructure, both inviting them to negotiate and daring them to oppose his proposal.“We’ll have a good-faith negotiation with any Republican who wants to help get this done,” Mr. Biden said. “But we have to get it done.”That last line was a not-so-subtle hint about his legislative strategy. If the president cannot win backing from Republican lawmakers, Democrats appeared poised to once again use a parliamentary budget tool known as reconciliation to push through the tax and spending plan with a simple majority vote and most likely only Democratic support.At an event in his home state on Thursday, Mr. McConnell called Mr. Biden “a first-rate person” whom he liked personally. But he argued that the president was running a “bold, left-wing administration” and warned “that package that they’re putting together now, as much as we would like to address infrastructure, is not going to get support from our side.”For Mr. Biden, who spent more than three decades in the Senate, the political calculations are far different than they were 12 years ago, when a similar measure was under consideration.Senator Mitch McConnell of Kentucky, the Republican leader, warned that his conference would not support Mr. Biden’s proposal.Anna Moneymaker for The New York TimesPresident Barack Obama took office in 2009, in the middle of an economic crisis with a Senate firmly in Democratic control. Only weeks into his term, he pushed through an $825 billion stimulus bill devised to jump-start the economy — legislation that is now seen by many progressives as far too timid.Mr. Obama and his aides spent weeks feverishly negotiating with conservative Democrats and a handful of Republicans in Congress, who pressed the president to limit the size of the spending plan. Rahm Emanuel, Mr. Obama’s chief of staff at the time, said conservative Democrats like Senator Ben Nelson of Nebraska insisted that the president win Republican support.Mr. Biden appears to have taken from that experience the lesson that there are limited benefits from seeking to woo a small number of Republicans — and that the key is to sell the benefits of the plan to Americans and not get hung up on the process to pass it.“The politics was different, the policy was different, the public was different,” Mr. Emanuel said, praising Mr. Biden’s approach. Even before the president unveiled his plan, Republicans argued that Democrats were not genuinely interested in bipartisan negotiations, particularly after they pushed the pandemic relief package into law without any Republican votes.Senator Chuck Schumer of New York, the majority leader, has asked the Senate parliamentarian to offer guidance on how many times senators can pursue reconciliation this fiscal year, which several Republicans took as a sign that they were preparing to bypass the 60-vote filibuster threshold.“It is disingenuous for the president to invite Republicans to the White House and the Oval Office to discuss this when he’s made it very clear — and Democrats in Congress have made it very clear — they have no intention of working with Republicans on this package,” said Representative Kevin Brady of Texas, the top Republican on the House Ways and Means Committee.In an interview, Senator Susan Collins, Republican of Maine, said she appreciated the outreach from the administration leading up to Mr. Biden’s announcement, including multiple bipartisan briefings for lawmakers and individual conversations with cabinet officials.But Ms. Collins, a member of a bipartisan Senate group that is eager to strike compromises on a number of issues, said bipartisan negotiations would most likely falter if the administration refused to budge on the overall price tag or composition of the package.Senator Susan Collins said she appreciated the outreach from the administration leading up to Mr. Biden’s announcement.Anna Moneymaker for The New York Times“Everyone knows what bipartisanship means: It means that you get members of Congress from both parties working on and voting for important legislation,” she said, adding: “It’s not like it’s some relic of ancient times. We acted in a bipartisan manner on the most important issue last year: the pandemic.”If Democrats are already considering using reconciliation, Ms. Collins said, “that raises questions about whether there is a sincere interest in crafting a bipartisan infrastructure package.”Some Democrats have said that the proposal is not enough to address both infrastructure needs and inequities across the country, and they have counseled the White House against winnowing down a legislative package to win a handful of Republican votes.“I’m not particularly hopeful that we’re going to see a giant awakening from Republicans who decide that they want to pass an infrastructure package that actually addresses climate,” Representative Pramila Jayapal of Washington, the chairwoman of the Congressional Progressive Caucus, told reporters before Mr. Biden’s speech. More