Washington (AFP) - Many expected -- or feared -- Joe Biden would stumble as he addressed Congress in his final State of the Union address before the November election. Instead, the oldest-ever US president came out swinging.

With jokes, retorts to hecklers, soaring rhetoric and a minimum of his customary mangled phrases, Biden defied critics.

Each stammer, slip of the tongue or confused look by Biden tends to be intensely scrutinized in the United States as he runs for reelection -- with Republicans painting each error as evidence that he cannot govern.

On Thursday, Biden got cheers from his Democratic party members.

"Four more years!" they chanted as Biden hammered his Republican rivals and laid out the case for a second term with a pugnacious energy that seemed to bely his 81 years.

To the great relief of lawmakers in his party, acutely aware of how heavily his age is weighing in the presidential race, Biden was in rare form, showing stamina in an hour-plus speech, speaking in a clear tone and quick clip, taking jabs at Republicans, and offering sprinkles of humor.

"I know it may not look like it, but I've been around a while," he grinned.

His Democrats, many of them dressed in white in honor of women's rights, lapped it up. They rose to their feet as Biden spoke, with the president even getting compared later to a fiery Baptist preacher.

MAGA hats

Absent any major Biden blunders, the Republicans -- many of them Donald Trump loyalists -- remained in their seats and mostly held their tongues.

After a speech last year marred by repeated shouting, the new Republican speaker of the House, Mike Johnson had implored his members not to stoop to heckling. 

Still, some did, and Biden punched back with vigor.

Some acolytes of Trump, who is almost certain to face the incumbent Biden in November, sought to score points. As soon as Biden entered the crowded House chamber, congresswoman Marjorie Taylor Greene, known for often outrageous antics, donned a red "Make American Great Again" cap as she approached the president.

Upon seeing her, Biden took a step back and let out a humorous "Oh!"

Greene had already made waves during last year's State of the Union by calling the president a "liar" mid-speech.

On Thursday, several Republicans repeated the accusation, but Biden appeared unruffled.

Frustration with the president was not limited to the Republican side. A group of progressive women lawmakers, wearing Palestinian keffiyehs, remained rooted to their seats throughout his address, in protest of Biden's support for Israel in the Gaza war.

When Biden addressed the Gaza crisis, Palestinian-born congresswoman Rashida Tlaib and others held up paddles with the message "stop sending bombs."

Biden soldiered on. And on.

After wrapping up his fiery address, he stood in the well of the chamber for more than 25 minutes, shaking hands and clapping backs, taking selfies with congressmen and senators, sharing a word with military generals and generally outlasting Republican rivals.

When Speaker Johnson adjourned the session and the lights dimmed, Biden was still on the House floor, holding court with lawmakers.