How might a 21st Century version of "I Have a Dream" be similar or different from the
original?

This question refers to Martin Luther King's speech "I have a dream" and the answer is open to the personal interpretation that each one has. Anyway, I will give you an answer from my point of view that you can use as an example or modify as you like, based on what you believe.

Explanation:

 This speech by Martin Luther King was recited in the year 1963, in which he sought equality between races for the future.

A current version of this speech would not be that different from the original.  

Although slavery no longer exists today, discrimination against people because of their skin color continues to exist.

The phrase "I have a dream that my four little children will one day live in a nation where they will not be judged by the color of their skin but by the content of their character." it could fit perfectly into a speech of this century.

However, we know that this struggle continues, we can see it in the protests that took place this year and the support of the vast majority of people, because we all have the same dream and we want this to change in the future.

- "about the claims : -

making a claim is just a fancy way of saying that you're stating your main point.' claims are not just opinions. a claim tells what you think is true about a topic based on your knowledge .

about the country claims : -

a counterclaim is just the opposite of a claim. counterclaims are also provable and supportable by reasons and evidence. not just, 'because i said so.' when you're planning an argument, you need to know what the counterclaim might be so that you can make sure that you disprove it with your reasons and evidence your research." - (catherineroberts)