"Hosni Walker" say the picket signs outside of the Wisconsin state capitol, in Madison, where some 20,000 state workers and supporters have massed in freezing weather to protest Governor Scott Walker's plans to revoke their collective bargaining rights. It's a persona the new governor, a Republican elected with Tea Party backing, seems to embrace; he has even threatened to call out the national guard in case of any "disruptions". Indeed, the Mubarak analogy is one thing on which both sides seem to agree: Glenn Beck has warned that the protests are the beginning of an Egypt-style "insurrection", and likens Wisconsin's public sector unions to the Muslim Brotherhood.

Busting up unions is, of course, nothing new in the US. Using military force to do it is rarer, but not unprecedented either: Walker's threat harkens back to the West Virginia mineworkers' strike of 1920, in which the government used federal troops and even a squadron of aerial bombers against its own citizens.

Nor is Wisconsin alone in declaring war on civil servants. Governors and state legislators in Ohio, Tennessee, Indiana, Nevada, New Jersey and Florida have advanced similar measures designed to revoke or restrict union rights, eliminate salary schedules and cut compensation to state employees.

Governors who are less prone to macho posturing than Walker are pleading poverty – "we're broke!" they say. And indeed, they are. Although, as critics note, Wisconsin wasn't broke at all – in fact, projected to enjoy a surplus – before a $140m spending package and series of tax cuts Walker pushed through in January (Walker says Wisconsin is currently $137m in the hole; the state fiscal bureau disputes this). States have dealt with budget gaps before, usually with strategic layoffs, furloughs and service cuts. Revoking union rights, on the other hand, doesn't save states any money right now.

It's a political, not budgetary move, designed to punish unions who backed the losing side last November.

Politicians have long found unions to be a convenient scapegoat when facing problems of their own making. What is notable is not that unions are taking it on the chin, but rather which unions: not mobbed-up Teamsters or do-nothing autoworkers, but teachers and firefighters, the previously untouchable heroes of small town America. It says something about the direction of American politics that New Jersey Governor Chris Christie has made trashtalking public school teachers the centrepiece of his political career.

With private sector union membership in freefall, it could be said that public sector unions are the only ones left to beat up. But the fact that garbage collectors have come to replace al-Qaida terrorists and Mexican landscapers as the right's bogeyman-of-choice can't be explained simply as an anti-union backlash. Fundamentally, it's an anti-public sector backlash, made possible by real cyclical tax revenue shortfalls and rising healthcare costs, and ginned up by politicians who failed at basic accounting.

Until now, bashing state workers has paid off handsomely. At a time of 10% unemployment, talk of lazy bureaucrats cashing fat paychecks is explosive, and can fuel anything from a GOP voter registration drive to a kamikaze attack on an IRS building. Underlying this anger, too, is a healthy dose of envy. As one Tea Party counter-protester fumed:

"Their benefits are so much better than mine and their pay is so much better than mine, but they are still crying."

In other words, if I can't have a good job, I'll be damned if anyone else gets to have one. Unions used to brag about their benefits to recruit new members; now, they have to hide them.

But if the protests in Madison are any indication, there is a limit to how much elected officials can demonise their own employees before they start to push back. A precursor to Wisconsin's revolt of the bureaucrats happened last year in Washington, DC, when incumbent Mayor Adrian Fenty was ousted in an election widely seen as a referendum on teachers' unions. As part of a sweeping overhaul of the teacher evaluation system, Fenty had empowered public school chancellor Michelle Rhee to fire teachers at will.

She did: 300 in a single week. The move was supposed to send a strong message that the mayor was serious about improving schools; instead, it provoked voter outrage. Neither Fenty nor Rhee considered that, in a city with a 17% poverty rate, government jobs are one of the few paths available to families seeking a middle-class standard of living, and a lot of those teachers were people's friends, neighbours and family members.

In Wisconsin, Walker was probably caught off-guard by the anger his announcement provoked. He may yet hold the line, and is under considerable pressure not to give in. As in Bahrain, Libya and Yemen, there are governors in other states who are fearful of the consequences if he does.