Florida Gov. Ron DeSantis (R) says that, as president of the United States, he will "shut the border down." 

DeSantis, according to the Daily Wire, said as much during a campaign stop in Iowa last week. The stop was at U.S. Sen. Joni Ernst’s (R-IA) annual “Roast and Ride” event.

This comes after DeSantis recently announced his 2024 bid for the U.S. presidency.

The announcement came after months of speculation and after months of polling that has consistently indicated that DeSantis is former President Donald Trump's only real Republican rival for the party's presidential nomination.

That being said, DeSantis still finds himself significantly trailing Trump in the polls, by dozens of percentage points on average.

DeSantis, however, is looking to make some inroads into Trump's lead by taking strong positions on key issues, such as the U.S.-Mexico border crisis.

At the "Roast and Ride" event, DeSantis said that he will do what other Republican presidents have failed to do, namely, completely shut down illegal immigration at the southern border.

“I’ve heard, as a Republican, talk about this southern border for years and years and years,” DeSantis said. “I will finally be the president to bring this issue to a conclusion. We will shut the border down.”

DeSantis added, "we will build a border wall. We will end mass migration into this country. And, we will hold the Mexican drug cartels accountable for the carnage they have unleashed on the American people."

The southern border issue brings up an important point about the developing Trump-DeSantis rivalry, namely, that both candidates are putting out the same message on many of the key issues, and that message largely originates from Trump.

It is Trump, of course, who, in 2016, campaigned on "building the wall" as a means to get illegal immigration under control. And, Trump managed to make significant progress with regard to this goal despite staunch opposition from congressional Democrats.

In other words, this Trump-DeSantis rivalry is shaping up to be one of those situations in which it is not really going to be the issues that determine whether one votes for DeSantis or Trump.

Rather, it is going to be something else that causes the voter to choose either Trump or DeSantis, such as personality or perceived ability to get the job done, or perceived ability to beat the Democratic nominee in the 2024 election, etc.

So far, as stated above, Trump is dominating the matchup.