By Cokie Roberts and Steven V. Roberts

President Trump has virtually no experience running a government or reading the Constitution. But now he’s getting a painful civics lesson about one of the principle precepts underlying American politics: checks and balances.

Some of those checks are written into law: the power of federal judges to block unlawful rules, or the independence of tenured officials like the head of the FBI.

Other checks are less formal, like the ability of the press to scrutinize a president through relentless reporting and fact-checking. Or like public opinion, which can sap a president’s leverage and credibility when his popularity sinks.

All these barriers, and many others, have restrained and restricted the new president during his first two months in office. The most powerful man in the world is discovering that running a country is far more difficult than running a business.

Of course, Trump retains enormous assets. He still has the bully pulpit, which he used to stage a boisterous rally in Kentucky that generated support for his health care proposal. He can still twist the arms of wavering Republicans, who have a deeply vested interest in his success.

He has stocked the federal government with appointees who promote his policies on issues like climate change. He can make executive decisions, like accelerating the deportation of undocumented immigrants. And one of his most important powers was on display this week as his nominee to the Supreme Court, Neil Gorsuch, seemed poised to win Senate approval.

But a political highway filled with speed bumps and stop signs is thwarting him in other ways.

Start with Republicans in Congress. All of them represent their own constituencies, whose interests and values might not coincide with the president’s. As a result, lawmakers from states with aging populations objected strongly to his proposals that would boost health insurance premiums for older policyholders.

Others — joined by many Republican governors — were furious over proposed spending cuts that would harm specific regions, like the Great Lakes, or target useful programs like job training or Meals on Wheels. Rep. Hal Rogers of Kentucky, an influential figure on the Appropriations Committee, called Trump’s budget “draconian, careless and counterproductive.”

A growing number of Republicans are also alarmed by the president’s penchant for fabrication, urging him to recant his baseless charge that he was wiretapped by the Obama administration. “It never hurts to say you’re sorry,” Rep. Will Hurd of Texas, a former CIA agent, told ABC.

Democrats on Capitol Hill have little real power, but they can still ask questions, shine spotlights and voice protests. Rep. Adam Schiff of California used a Congressional hearing to publicize the many connections between the Trump campaign and Russian interests.

Lawmakers can be vulnerable to White House pressures, but federal judges are not. Five different courts have now blocked Trump’s proposals to limit immigrants and refugees from majority-Muslim countries. And those judges don’t act in isolation.

The cases they ruled on were brought by powerful outside interest groups, like the American Civil Liberties Union, and attorneys general from Democratic states, who can mount legal challenges to a president’s more outlandish impulses.

Unlike federal judges, the head of the FBI is not appointed for life, but he does have a 10-year term, and that has enabled the current director, James Comey, to stand up to the president on two key issues. First, he flatly contradicted Trump’s claims that he’d been wiretapped by Obama. Second, he is pursuing a criminal investigation into possible links between Team Trump and Russian agents who attempted to influence the U.S. election.

Journalists also play a key role in restraining the White House. To Trump’s great frustration, the Washington Post revealed conversations between his national security adviser, Michael Flynn, and the Russian ambassador, prompting Flynn’s resignation. Even Fox News refuted spurious claims made by a contributor — and echoed by the White House — that the Obama administration had engaged the British to help in a wiretapping scheme.

Perhaps the ultimate check on presidential power is public opinion. No president can govern effectively without popular support, and Trump is rapidly squandering that precious and irreplaceable asset.

While he won 46 percent of the popular vote, his favorable rating in the latest Gallup poll has plunged to 37 percent. That’s the lowest score for any president after two months in office since Gallup started measuring presidential popularity in 1945.

The president is learning a hard truth: The American system was deliberately designed to impede intemperate and irresponsible leaders — just like him. And the system is working.

(Steve and Cokie Roberts can be contacted by email at stevecokie@gmail.com.)