There’s a new political boss in Venezuela. So far, he’s acting just like the old boss.

Hugo Chávez was purportedly still in his death throes last week when his designated political heir, eager to snatch the reins of power before anyone could stop him, signaled that he was just as capable of playing the anti-American card as the dying president by summarily expelling two U.S. military attachés from the U.S. Embassy in Caracas.

The stated reason — that they were conspiring against the Venezuelan government — is nonsense. No evidence was put forward. But it conveniently served as a way for Vice President Nicolás Maduro to let Venezuelans know early on that (1) he was in charge and (2) he intends to follow in the late president’s political footsteps.

The anti- yanqui gesture was a dramatic way of conveying Mr. Maduro’s intentions, accompanied by ugly rhetoric about “historical enemies” (the United States) and even insinuating that sinister forces caused Mr. Chávez’s fatal bout of cancer.

All of this even before the body was cold. It was Mr. Maduro’s way of reassuring supporters that he deserves to wear the mantle of Chavismo, the prevailing socialist ideology of the Venezuelan state fashioned by the late leader, and of keeping would-be rivals at bay.

He followed this up with another act worthy of the man he wants to succeed by ignoring the plain words of Venezuela’s constitution in a bold grab for power. The document decrees that in the absence of a president, the role of interim chief of state belongs to the head of the National Assembly — another Chávez acolyte named Diosdado Cabello — until elections are held and a new chief executive is elected.

Not that anyone ever accused Mr. Cabello of being a paragon of democracy. But this is Hugo Chávez’s own constitution, after all, the same one he promulgated shortly after becoming president in 1999 to ease his path to greater power.

But never mind the constitutional niceties. Legal obstacles never stood in Mr. Chávez’s way, and so it will be, apparently, for his successor. Mr. Maduro, close to the Castro brothers in Cuba, proclaimed himself interim president and the rest of Chávez’s inner circle obediently fell into line.

None of this bodes well for the expressed U.S. desire to have a more productive relationship with Venezuela, the fourth largest supplier of U.S. oil imports.

Mr. Maduro may yet surprise. He’s in full campaign mode for next month’s presidential elections and this is no time to deviate from the Chávez doctrine by reaching out to those countries the former president identified as enemies of Venezuela.

But the signs are not good. This week, the last TV outlet critical of the Chávez regime, Globovisión, threw in the towel after years of government intimidation and agreed to sell its business to a Chávez ally after the election in yet another blow to freedom of expression.

U.S. officials should continue to seek areas of productive cooperation with Venezuela — counter-narcotics and counter-terrorism, for example. But they should never hesitate to speak out in defense of democratic principles, starting with vigilance leading to the presidential election.

If Mr. Maduro wants to show that he has nothing to fear in a free and fair election, he should invite international election observers to monitor the vote. Hugo Chávez scoffed at election observers, but Mr. Maduro should welcome their presence. It would be the best way to show that he’s his own boss.