Loved, hated and feared, Donald Trump has proved once again that he is the most resilient politician in modern American history.

Neither the ridicule of the political establishment toward the idea that he could win the White House nor the two-year investigation by a special counsel nor impeachment by the House of Representatives has bowed Trump or even prompted him to temper the brash, blunderbuss style that has brought him this far.

The Senate acquitted the president Wednesday of two articles of impeachment that charged he abused power by pressuring Ukraine to investigate a political rival, then obstructed Congress in an effort to cover it up.

Trump cheered the unsurprising verdict as vindication. Rep. Adam Schiff, D-Calif., the lead House impeachment manager, warned that the president may feel even more empowered and emboldened as a result, having rebuffed the Constitution's most severe penalty.

The vote didn't even come close to the two-thirds majority needed to remove the president from office: 52-48 to reject the first article of impeachment, on abuse of power, and 53-47 to reject the second, on obstruction of Congress. Partisanship prevailed, with one exception: Every member of the Democratic caucus voted "guilty" on both counts. Every Republican voted "not guilty" on the second count, but Mitt Romney of Utah crossed party lines on the first count, calling Trump guilty of abuse of power.

Surviving impeachment isn't the same thing as winning a second term, of course.

Trump's resilience will be tested again in November, when he will be the first impeached president to stand for reelection. He faces legal investigations into his family business, his personal finances, his inaugural committee and his now-defunct foundation.

That said, three years after many thought Trump would never win the presidency, almost everyone acknowledges there is at least a credible chance he will win it again. That victory would put him in the most rarefied ranks of American politics, including 17 of his predecessors who won election and reelection to the White House.

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'He seems like an unsinkable ship'

"There is absolutely no doubt that Trump has weathered a dozen or more scandals, moments, mistakes that would have destroyed most any other candidate or president in American history," said Jeffrey Engel, director of the Center for Presidential History at Southern Methodist University. "We called (Ronald) Reagan the 'Teflon president.' We need to invent a new material just to describe his ability to deflect otherwise fatal wounds."

Trump's calamities are often self-inflicted, Engel said, created by his business practices, his approach to politics, his unfettered rhetoric.

"Trump's knack is to roll from one crisis to another," said Larry Jacobs, director of the Center for the Study of Politics and Governance at the University of Minnesota. "He seems like an unsinkable ship."

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Democrats cite their victories in the 2018 midterm elections, including winning control of the House of Representatives, as a sign of Trump's vulnerabilities.

At the opening Iowa caucuses Monday, Democratic voters by 61%-37% said in the ABC Entrance Poll that they would rather see the party nominate the candidate with the best chance of winning, not the one who agreed with them most on issues.

That said, Democrats haven't reached a consensus on which presidential contender and what policy approach would fare best against Trump, whose ability to withstand furors has flummoxed many of them. Their frustration was on display at the combative State of the Union address Tuesday night.

The capacity to weather a storm, to rebound after a blow that might have crushed others, may be the single most essential trait of successful political leaders. Campaigns are typically rough-and-tumble contests, and serving in office draws what can be withering scrutiny of an official's current decisions and past behavior.

Consider this: Allegations of marital infidelity prompted Colorado Sen. Gary Hart to suspend his campaign for the 1988 Democratic presidential nomination; he never ran for elective office again. Four years later, despite a firestorm over stories that he had engaged in an extramarital affair and dodged the draft, Arkansas Gov. Bill Clinton rejected calls for him to drop his bid for the 1992 nomination.

When he managed to finish second in the New Hampshire primary, Clinton declared himself the "Comeback Kid." That put him on course to win two terms in the White House.

"I'm like one of those Baby Huey dolls," he told playwright Anna Deavere Smith in 1997, a reference to a plastic inflatable figure with a weighted base. "You punch 'em, and they come back up."

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Like Trump, Clinton survived impeachment, able to serve out his second term after being acquitted by the Senate. President Richard Nixon was also famously resilient through his up-and-down political career, though it came to an abrupt end when he resigned from the White House in the face of his near-certain impeachment and conviction.

There are ways in which Trump's resilience is more notable than his modern predecessors, in part because it seemed less likely.

Trump set out for the White House with no experience in running for office or holding it. Clinton was in his fifth term as governor of Arkansas when he prevailed in the marathon that is a presidential election. Nixon had been a California House member and senator, then a two-term vice president. In contrast, Trump's first bid for electoral office was for the top job.

At the time, he was derided by many in the Republican establishment, at least until he began defeating his more seasoned rivals in the 2016 primaries, among them Jeb Bush, the heir of a GOP dynasty. In the general election, he defeated Hillary Clinton, a member of the dominant Democratic family of the day.

What's more, Trump has persisted through one crisis after another without feeling the need to make course corrections.

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Nixon fashioned himself a softer-focus "New Nixon" for his 1968 bid for the White House, winning it eight years after he had lost. Clinton adopted a new strategy of bipartisan cooperation called triangulation after his party suffered disastrous defeats in the 1994 midterm elections, and he expressed regret for his behavior after he was acquitted of impeachment charges by the Senate.

No brakes on the bulldozer

Trump continues to post provocative tweets, repeat assertions shown to be untrue, savage political opponents and rely on controversial outside advisers such as former New York Mayor Rudy Giuliani despite the furor those steps have created. The top aides from the early days of his presidency who tried to put brakes on his bulldozer approach are mostly gone.

All that may eventually catch up with him. He depends on the fervent backing of his solid base; even his record 49% job approval rating in the latest Gallup Poll is just 3 points higher than his share of the 2016 electorate. He lacks any of the bipartisan bonhomie that has helped some other leaders survive a crisis abroad or economic downturn at home.

"The brilliance of Reagan's resilience is that he not only survived but thrived with strong, sustained popularity for long periods of his presidency," Jacobs said, a crucial asset when the Iran-contra scandal erupted on his watch. "Trump survived, but he is the most unpopular president in modern times."

Even as he was being impeached, few in Republican officialdom warned Trump to curb his instincts.

Other presidents since World War II have enjoyed periods of enormous popularity, but none of them held such an iron grip on his party. Not a single GOP House member voted to impeach Trump. In the Senate, Romney, the party's presidential nominee in 2012, was the sole, lonely Republican who broke with Trump to vote for conviction for abuse of power.

In an emotional speech on the Senate floor, Romney said he was braced for the consequences.

Donald Trump Jr., the president's son, quickly posted a picture on Instagram hurling an insult at Romney and calling for him to be expelled from the Republican Party.