President Biden delivered an energetic and impassioned speech that was as much a campaign kickoff as it was a State of the Union, leveraging what is expected to be one of his largest audiences of the year to make a forceful case that he was fit enough for another four years.

Mr. Biden has rarely been called a bold orator. But he arrived on Capitol Hill on Thursday with the benefit of mercifully low expectations after unrelenting Republican attacks on his mental and physical fitness.

This was not a typical State of the Union. The speeches are often a laundry list of accomplishments and an equally long set of promises. Instead, this was Mr. Biden framing the year, just as his White House and Wilmington-based advisers want, as a stark choice between two candidates.

He opened with Donald Trump. He closed with Mr. Trump. And in between he taunted and teased the Republican lawmakers in the chamber who were protesting and jeering, readily taking the bait — and even one person’s pin — to score political points of his own.

Here are five takeaways from Mr. Biden’s fiery election-year State of the Union:

A feisty speech aimed at combating the notion that Biden is too old.

Mr. Biden came into Thursday’s speech determined to use the high-profile moment to beat back accusations that he is too old for a second term.