The driver’s likely ideology (based on the truck’s slogans: "NO SHAH. NO REGIME. USA: DON'T REPEAT 1953. NO MULLAH.") aligns closely with that of the People's Mojahedin Organization of Iran (MEK / PMOI / Mujahedin-e Khalq).

This group is known for its signature slogan "No Shah, No Mullah" (or very similar variants like "No Shah, No Regime, No Mullah"), which explicitly rejects:
- The restored/returned monarchy (Shah / Pahlavi dynasty, often supported by monarchist protesters),
- The current theocratic Islamic Republic (mullahs / clerical regime).

The MEK combines elements of revolutionary leftism (Marxist-influenced class struggle, anti-imperialism) with a reinterpretation of Shia Islam, pushing for a secular democratic republic, gender equality, separation of religion and state, and opposition to both past monarchy and present theocracy.

The added warning "USA: DON'T REPEAT 1953" (referring to the CIA-backed coup against Mosaddegh) fits the MEK's long-standing anti-imperialist stance and suspicion of U.S. interference — they oppose foreign-imposed regime change (whether restoring the Shah in '53 or any new puppet today).

While some reports describe the slogans as "pro-Ayatollah" (likely a misreading by observers unfamiliar with opposition factions), the phrasing is distinctly anti-regime and anti-monarchist, characteristic of MEK-aligned third-way dissidents rather than regime loyalists.

In the Iranian opposition diaspora, this position often puts MEK supporters at odds with pro-Reza Pahlavi monarchists (who dominated the LA protest), explaining the violent clash.

So: MEK-style leftist-Islamic revolutionary opposition — anti-Shah, anti-mullah, anti-U.S. meddling, pro-secular democratic revolution led by Iranians themselves.