CNN  — 

Confirmation duels over Joe Biden’s Cabinet picks have suddenly turned nasty, ringing alarm bells about the cliffhanger nature of a 50-50 Senate and bitter fights to come over the President’s ambitious agenda.

Growing intrigue over a trio of controversial presidential picks is also underscoring the power of individual senators such as Democrat Joe Manchin of West Virginia and Republican Lisa Murkowski of Alaska, when the partisan balance is so evenly divided.

While Biden has seen blue-chip national security selections such as Antony Blinken as secretary of state and Lloyd Austin at the Pentagon installed, the focus on nominees whose portfolios touch on some of the most sensitive domestic political issues is bringing the confirmation process to a contentious crescendo.

The nomination of Neera Tanden, Biden’s pick to lead the Office of Management and Budget, is in deep peril after Manchin jumped ship and a string of Republicans signaled they couldn’t support her.

Another bruising hearing is looming on Tuesday, for interior secretary nominee Deb Haaland, whose opposition to fossil fuels has GOP members branding her as extreme, in a showdown that could also prove uncomfortable for moderate Democrats.

And Xavier Becerra, chosen by the President to lead the Department of Health and Human Services, has emerged as a culture war lightning rod over his stance on abortion and Obamacare, a perennial fault line between Republicans and Democrats.

It’s not at all unusual for new presidents to run into trouble with some nominees – or even to see several potential Cabinet members fall. Blocking a pick is one easy way for senators to flex their power and signal to a new White House that they can’t be taken for granted. And the policy clashes clouding the confirmation hopes of candidates such as Haaland and Tanden are quite predictable, since they mirror the chasms between the parties.

But when a president has a reasonable governing majority in the Senate, confirmations become easier. If Democrats had a handful of seats to spare, for instance, a senator such as Manchin, who must constantly judge the winds in his ultra-conservative state of West Virginia, could be given a pass.

But when nominations depend on a party-line vote and a tiebreaker cast by Vice President Kamala Harris, Democratic leaders can’t offer any political cover – at least without some defections from GOP ranks.

For now, the problem concerns individual Cabinet nominees – whose defeat would sting for Biden and dent the bodywork of his governing machine. But in months to come, when it comes to sweeping and electorally radioactive issues such as climate change and immigration, his entire presidency will be on the line.

While the situation is fraught now, it is not out of the question that an illness, incapacitation or even death among elderly senators could erase his governing majority for good.

A nomination on the brink

Tanden’s struggles are characteristic of nominees who have issues stemming from their own political vulnerabilities but who also fall victim to wider political forces beyond their individual fates.

Still, Tanden, the president of the liberal think tank Center for American Progress, is in the slightly unique position of seeing her support fray on the right and the left – a scenario that led some observers to register surprise when she was nominated.

Republican senators profess they are offended over some of her now-deleted tweets that blasted the GOP and individual senators who she now needs to vote for her. Of course, it’s a little rich for Republicans to complain about anyone’s tweets after spending four years enabling a president whose social media vitriol left Tanden in the dust. And then there is the question of whether Tanden, a prominent female political figure born to Indian immigrant parents, is a victim of prejudicial double standards.

Still, hypocrisy is the grease that often makes the wheels go ‘round in the Senate. And Tanden also has lukewarm support from her own side. She was forced to try to make up with Sen. Bernie Sanders, a Vermont independent who caucuses with Democrats, who now chairs the Budget Committee and would be her principal contact. Sanders’ supporters accused Tanden of being among Democratic elites who they believe stacked the party’s nominating race against him and in favor of former Secretary of State Hillary Clinton in 2016. During her confirmation hearing, Tanden had to apologize for what Sanders complained were her “vicious” attacks on progressives.

Given her always-questionable prospects, there was not much incentive for a senator such as Manchin to support her. The West Virginian has backed the President’s nominees who have come up for full votes so far. And he voted to convict former President Donald Trump in his Senate impeachment trial – in what was an unpleasant choice since his home state overwhelmingly supports the ex-President.

So to safeguard his brand as a relatively independent voice, and to avoid being tarred as a rubber stamp for Biden, Manchin probably needed to make a stand somewhere. He explained that he could not support Tanden because she represented the kind of divisive politics that Biden wants to purge from Washington.

“I don’t know her, probably a very, very good person, just basically a little bit toxic right now,” Manchin told reporters on Capitol Hill on Monday.

The senator from West Virginia is also emerging at a pivot point of the battle to pass Biden’s $1.9 trillion Covid relief bill, which all Republicans are likely to oppose. He said Monday that he would seek to amend the legislation to set a federal hourly minimum wage at $11 over two years, instead of the current Democratic proposal for a hike to $15 over five years.

Once Manchin cut Tanden loose, and after a string of Republicans – including Sens. Mitt Romney of Utah, Susan Collins of Maine and Rob Portman of Ohio – followed suit, her prospects of confirmation became dire indeed, despite the White House insisting that it was standing by the pick Monday.

“They’re going to have to pull her,” one senior Democratic senator told CNN’s Manu Raju. Tanden’s thin hopes late Monday probably relied on Murkowski, who has yet to say how she will vote.

The Alaska Republican is an independent voice – and she voted to convict Trump in his second impeachment trial. But it’s hard to see how she would have an incentive to rescue an already deeply embattled Democratic Cabinet nominee, especially with her own reelection race looming next year.

Proxy battle over climate change

The Haaland nomination differs from the Tanden case since the House member from New Mexico is highly popular among most Democrats. Her nomination is historic since she would be the first Native American Cabinet member. She would also lead the Interior Department, an agency with a long record of discrimination against her community.

Democrats and White House officials told CNN on Monday that they anticipate a tense few hours when Haaland appears before the Energy and Natural Resources Committee on Tuesday.

And guess who could be the key Senate voice on the panel and in the full Senate on Haaland’s prospects? Manchin again, who chairs the committee and has not yet committed to supporting her nomination.

“We’re very open to hearing her, and hopefully she’ll have a good hearing,” Manchin, a longtime supporter of fossil fuel industries in his home state, said Monday.

Haaland is at risk of becoming the focal point of Republican attacks on Biden’s recommitment of the United States to fighting global warming – which saw him quickly rejoin the Paris climate accord after taking office.

In the past, Haaland has opposed the issuing of new oil and gas drilling leases on federal land and has expressed support for a ban on fracking, a method of extracting natural gas. She has also supported the Green New Deal, the ambitious climate plan pushed by Democratic Rep. Alexandria Ocasio-Cortez of New York – though not the Biden administration.

The Green New Deal has been the target of Republican attacks claiming its restrictions on fossil fuels would destroy the US economy. It’s likely Tuesday’s hearing will turn into a preview of the bitter partisan battles likely to unfold when Biden sends a climate bill to Capitol Hill.

A hearing – at last

Not all Biden’s nominees slipped into trouble on Monday.

The pick who waited longest to get a confirmation hearing – nearly five years, to be exact – is attorney general nominee Merrick Garland. The former DC Circuit Court of Appeals chief judge was nominated by President Barack Obama to be a Supreme Court justice but was blocked for months by Senate then-Majority Leader Mitch McConnell, R-Kentucky, in a power play that paved the way for the current conservative majority on the court.

Ironically, the reputation for moderation and steady temperament that Obama thought might ease Garland’s way through a Republican-led Senate to the high court helped him on Monday in his confirmation hearing.

Arch-Trump supporter Republican Sen. Lindsey Graham of South Carolina said Monday that he would “most likely” support the nomination.