Donald Trump, responding to recent attacks by Republican presidential rival Nikki Haley, asserted that he feels “sharper now than 20 years ago” and proposed that presidential candidates undergo cognitive tests.

This comes as Haley questioned the mental capabilities of both Trump, 77, and President Joe Biden, 81, due to their age. Speaking at a Nevada rally, Trump aimed to diminish Haley’s candidacy while positioning himself for a potential general election rematch with Biden.

Having secured wins in Iowa and New Hampshire, Trump is almost assured of the Republican nomination, but he is pressuring Haley, his last remaining rival, to withdraw before the South Carolina primary on Feb. 24.

Despite Trump’s efforts, Haley has refused to back down, challenging him to a debate as the ultimate mental competency test for presidential candidates.

In his speech, Trump targeted Haley with a demeaning nickname, calling her “birdbrain,” and accused her of being “almost a radical left Democrat.” Trump emphasized the urgency to conclude the nomination fight, leading Haley in South Carolina polls, but she remains committed to campaigning beyond.

The speech also shifted focus to immigration issues, with Trump characterizing illegal border crossings as a “catastrophe” and an “invasion.” Meanwhile, Biden’s campaign has intensified attacks on Trump, portraying him as a threat to U.S. democracy and linking him to the Supreme Court’s 2022 decision on federal abortion rights.

As the political landscape intensifies, Trump’s remarks and strategies underscore the dynamics of the Republican nomination race and his preparations for a potential showdown with Biden in the general election.