After a month of wrangling, Argentine President Cristina Kirchner succeeded in sacking central bank President Martin Redrado last week. In his place she named Mercedes Marcó del Pont, a Yale-trained economist who has expressed the view that central bank autonomy ought to be limited.

The opposition howled at the news. Felipe Sola, former governor of Provincia de Buenos Aires, warned that the new bank president "is going to do what the executive decides and they are going to modify the bank charter to justify her doing what the executive tells her."

Of course that would seem to be the point. Mr. Redrado was fired because he refused to turn over $6.6 billion in bank reserves to Mrs. Kirchner, who wants to pay foreign creditors but doesn't want to use treasury revenues. Ms. Marcó del Pont, if she wants to keep her job, will follow the orders of the president.

Mrs. Kirchner is not the first politician to covet the wealth available from the monetary authority. Closer to home, there is Barack Obama, who didn't back Ben Bernanke's controversial second term as head of the Federal Reserve out of magnanimity. Mr. Bernanke kept his job because he has shown a willingness to finance Mr. Obama's big-government agenda.

Yet Americans can still hold out hope that competing institutions will check the runaway power of a government that is being underwritten by the central bank. In Argentina, institutions are frail and it is far from certain that they can hold up under Mrs. Kirchner's iron fist.

There's a lot at stake. More inflation—beyond the 17% rate in 2009—is one danger. A Hugo Chávez-style power grab is another. Mr. Chávez is Mrs. Kirchner's closest ally in the region, and she has been open about her desire to copy his model; her husband, former president Nestór Kirchner is widely viewed as the author of her playbook.

The lunge for the bank reserves is all about improving the Kirchners' odds of staying in power. Until last night when Mr. Kirchner underwent emergency circulatory surgery, analysts expected him, rather than her, to run in the 2011 presidential election. What remains clear is that if the kirchneristas want to retain power they will need to boost government spending.

Like any good socialist, Mrs. Kirchner already has run up expenditures. Revenues have not kept pace because tax increases have discouraged investment and legal economic activity. In March 2008, Mrs. Kirchner's effort to raise export taxes on farm products sparked nationwide protests.

None of this fazed her. In October 2008 she championed the confiscation of $30 billion of private retirement accounts, further undermining public trust. Distrust in the central bank dates back even further. In 2007, when Mr. Kirchner was president, he fired the head of the statistics agency that calculates inflation for failure to alter the agency's methodology so as to mask a rising price level.

The 2009 midterm elections demonstrated how unpopular the Kirchners have become. Their wing of the Peronist party took a beating and even Mr. Kirchner, who was at the top of the ticket in the Perónist stronghold of Provincia de Buenos Aires, could not defeat his rival.

Mrs. Kirchner responded to this first by forcing a new media law through the lame duck legislature. Established radio and television channels that criticize the government will now have a hard time getting licenses renewed; most airwaves will be reserved for nongovernmental organizations that the government chooses and for state-owned media.

That ought to help control the message, but Mrs. Kirchner knows that for convincing voters nothing works like cold hard cash. Last week her attorney general appealed a court ruling that went against her attempt to transfer the bank reserves to the treasury. If she loses that appeal, it is expected that she will get around the problem by making promises to the provincial governors as a way to secure the congressional votes she needs to change the law. If she succeeds, it is likely to be only a first step in a massive monetary expansion.

The Kirchners have a reputation for being power hungry, and what is important to them is what advances their agenda. Elisa Carrió, the leader of the opposition Civic Coalition, spoke for many last week when she expressed concern about bank autonomy and the first couple's ambitions. "The great debate is inflation and the use of reserves for the political interests of the first couple," Ms. Carrió said.

It can be argued that high levels of bank reserves are wasteful. Certainly that ought to be debated. But Mrs. Kirchner governs with a club, and her new central bank president has admitted she has no plan to maintain independence.

Former central bank President Alfonso Prat-Gay said last week he is worried that the president's proposed "economic council," consisting of members of the treasury and the central bank, will be "in the hands of the Kirchners." Mr. Prat-Gay is not alone.