Washington (CNN) Donald Trump was right: He can get away with almost anything -- a factor that is likely to mean an even more unchained presidency over the next 18 months.

All the reasons why Democratic efforts to check the President will likely fail were revealed in Attorney General William Barr's trial by fire on Capitol Hill on Wednesday and his refusal to submit to a second round before the fired-up House majority on Thursday.

The drama also showed that in the short span of a White House term, given certain partisan conditions, the modern political system will find it almost impossible to constrain a President -- especially one who poses such an overwhelming challenge to congressional custom as Trump.

Trump now has an attorney general, like a human block of granite, who sees few limits on presidential power and is willing to obfuscate and execute blocking movements on his behalf.

"He's an outstanding man. He's an outstanding legal mind," Trump said of Barr in an interview Wednesday night on the Fox Business network, adding that the attorney general did a "fantastic" job during the hearing.

After a day of taking lumps from minority Senate Democrats, Barr told the House Judiciary Committee he would not show up for a second day of testimony on Thursday.

The attorney general objected to Democratic plans to use staff attorneys in addition to often-scattershot lawmakers to pin him down with questions about the Mueller report. He likely faces a subpoena and yet another legal showdown between House Democrats and an administration that appears to hold their duty of congressional oversight in contempt.

In his defiance, Barr proved himself to be exactly the protective bulwark for which Trump pined but never had in characters like former Attorney General Jeff Sessions and former FBI chief James Comey.

"We have to stop using the criminal justice process as a political weapon," Barr told the Senate Judiciary Committee, even as he was accused of misrepresenting special counsel Robert Mueller's report to save Trump's presidency.

A hearing that was already destined to be tense turned red hot with news late Tuesday that Mueller had written to Barr in March to complain that the attorney general's four-page letter to Congress about the special counsel's principal findings did not convey sufficient nuance.

"This threatens to undermine a central purpose for which the Department appointed the Special Counsel: to assure full public confidence in the outcome of the investigations," Mueller wrote.

Barr was unrepentant.

"It was my baby, and I was making a decision as to whether or not to make it public," he said, when accused of framing the release of the redacted report to politically shield Trump.

"It was my decision how and when to make it public, not Bob Mueller's," he said.

Barr delivered for the President

JUST WATCHED Burnett: Clear Barr and Mueller at odds over findings Replay More Videos ... MUST WATCH Burnett: Clear Barr and Mueller at odds over findings 04:17

From Trump's viewpoint, the attorney general's performance on Capitol Hill validates his nomination completely and it cements the impression that he was handpicked to do what he's doing.

The President's success in getting rid of Sessions and leveraging Barr into place will go down as one of the most significant political lifts of his term.

After all, Barr had submitted an unsolicited memo to the Justice Department assailing Mueller's approach on obstruction in 2018. As the new attorney general, he decided there was no case to answer on obstruction after Mueller did not present a conclusion but presented damning evidence on which Congress could act.

Any notion that Congress could rein in the President was undermined by the antics of GOP senators who appeared more concerned with producing soundbites for Fox News opinion shows.

With a few exceptions, such as Iowa's Joni Ernst and Nebraska's Ben Sasse, who worried about election security, most Republican senators seemed to have an eye on Trump, no doubt glued to the TV.

Missouri's new senator, Josh Hawley, read out texts contemptuous of Trump voters from Peter Strzok -- who was fired from Mueller's team when the special counsel found out about his sentiments.

Hawley slammed the "open disdain, if not outright hatred" shown by Strzok, framing him as a symptom of a bureaucracy that "tried to overturn the results of a democratic election."

"That's what's really gone on here," said Hawley.

The effectiveness of Trump's daily effort to discredit Mueller and to use the deeds of Strzok to establish a damaging narrative in conservative media is reflected in the strong skepticism about the special counsel probe among GOP voters.

A CNN/SSRS poll published Wednesday shows that 44% of voters approve of Barr's handling of the Mueller report and 43% are critical -- with a wide partisan gap.

There is no political upside for Senate Judiciary Chairman Lindsey Graham to keep investigating Barr's conduct or to probe Trump's behavior in the 2016 campaign.

"I am not going to do anymore, enough already. It's over," the South Carolina Republican told reporters. "But I'm not going to retry the case."

Democrats see a different reality

JUST WATCHED Nadler: Barr won't testify because he is terrified Replay More Videos ... MUST WATCH Nadler: Barr won't testify because he is terrified 01:22

Befitting the achingly polarized Congress, Democrats saw an alternative reality.

They spent Wednesday telling Barr he had lied to Congress, was facilitating a corrupt President and was stifling the special counsel, who they say proved Trump had obstructed justice.

"You seem to have been the designated fall guy for this report," said Sen. Richard Blumenthal, D-Connecticut.

Democratic Sen. Mazie Hirono of Hawaii told Barr he had joined a list of people who had sacrificed their reputations for the "grifter and liar in the Oval Office."

"We know more about your deep involvement and trying to cover up for Donald Trump," Hirono said. "America deserves better. You should resign."

The administration, meanwhile, is busy ignoring a flurry of subpoenas meant to compel officials to testify or the handing over of political crown jewels like Trump's tax returns as mandated by law.

Democrats say the White House's resistance shows contempt for Congress, long-accepted traditions of governance and an open flouting of the Constitution.

If proved, this catalog of accusations adds up to a staggering abuse of presidential power. And Democrats have the power to do something about it -- the weapon of House impeachment hearings.

While Republicans would ensure Trump survives a Senate trial, Democrats could still force vulnerable GOP senators to put their careers on the line and beckon history's judgment to defend the President.

Yet there is no sign that they will live up to the implications of their words. Political anxiety about being perceived as overreaching by voters means they will likely continue to rhetorically indict Trump but not seek to oust him.

The CNN polls showed the impression that Democrats are taking investigations into Trump too far is growing. Thirty-eight percent of those polled thought so in March, and 44% do now. The shift is mostly among independents.

No price to pay

JUST WATCHED GOP panelist: I have no confidence Trump campaign would turn down Russia's help in 2020 Replay More Videos ... MUST WATCH GOP panelist: I have no confidence Trump campaign would turn down Russia's help in 2020 03:24

From Trump's point of view, there is little reason to moderate his aggressive norm-busting leadership. There's probably never going to be a price to pay.

Democrats in the House are certain to press on with their investigations. They will try to secure testimony from Mueller and key protagonists in the special counsel's report like former White House counsel Don McGahn. But without the threat of impeachment, they will be limited to using the investigations to make a case to voters in 2020 of Trump's unsuitability for a second term.

While he still has legal concerns, notably in probes into his financial empire by attorneys in New York, and the judicial branch can continue to countermand his executive actions, Trump doesn't face an existential threat to his presidency from his political foes in Washington.

Democrats, such as House Speaker Nancy Pelosi, may be reading the political winds correctly in their reticence to move to impeachment hearings to back up the party's serious allegations of abuse of power by Trump.

If he wins reelection, however, after escaping lasting political damage from the Mueller drama, the inquest over the Democratic failure to seriously wound a weakened presidency will go on for generations.