Story highlights Errol Louis: Experienced politicians sense weakness in Trump's administration

McCain's op-ed is a reminder of the divide between Trump and the GOP, Louis writes

Errol Louis is the host of "Inside City Hall," a nightly political show on NY1, a New York all-news channel. The opinions expressed in this commentary are his own.

(CNN) President Donald Trump is in for a bumpy political ride when Congress reconvenes after Labor Day. A remarkable number of leaders of the President's party have begun sharply criticizing Trump, signaling that he can no longer expect lawmakers to follow the White House's lead on major legislation.

The latest blast from Sen. John McCain of Arizona, who was elected to his sixth term in the Senate on the same day Trump won last November.

"Congress must govern with a President who has no experience of public office, is often poorly informed and can be impulsive in his speech and conduct," McCain wrote in a toughly-worded Washington Post opinion piece

"We must respect his authority and constitutional responsibilities. We must, where we can, cooperate with him. But we are not his subordinates. We don't answer to him. We answer to the American people. We must be diligent in discharging our responsibility to serve as a check on his power."

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In political terms, that's a declaration of independence -- one that could, over time, turn into a declaration of war.