Ed Morrissey writes at HotAir.com about one positive impact of Donald Trump’s pending return to the White House.

What a difference a day makes! Especially when that day was November 5th.For the last four years, Mexico stood by while Joe Biden threw open the borders and did nothing about the drug cartels. Millions of people illegally entered during that period and deadly narcotics flooded the country. Now that the American electorate voted for real border security and an end to narco-trafficking, the Mexican government has decided to act — before Donald Trump and his hardliners act first.

With Trump and his allies this year floating the use of American military force against Mexico’s drug cartels, Mexican officials have tried to learn whether he is serious or merely blustering to gain leverage in talks about shutting down the pipeline of migrants and drugs heading into the U.S. Mexico’s new president, Claudia Sheinbaum, has rushed to blunt criticism from Trump’s orbit and put to rest worries at home that there is any danger from the country’s neighbor to the north. …

Wonderful thing, elections.

This might be the most impactful presidential transition ever. Ronald Reagan got the hostages out of Iran by winning the election, but Trump is resetting the world stage well ahead of his inauguration. His upcoming term has forced world leaders to recalculate across the board, including on both of our national borders. Mexico barely lifted a finger under Joe Biden to deal with the narco- and human-trafficking cartels (which likely overlap anyway), because Biden never gave them a reason to take serious action.

Sheinbaum’s tone has changed considerably over the last few weeks too. …

Old and busted: Let’s build bridges! New hotness: Look at us — we’re busting people!Would this change have happened under Kamala Harris? Oh, let’s not always see the same hands … Not only did Harris run away from her status as Biden’s border czar, she couldn’t articulate a single policy of the Biden-Harris administration that she would change as president.