If last week's speech to Congress by Mexican President Felipe Calderon is any gauge, the U.S. relationship with its southern neighbor is taking on a strangely partisan overtone.
Democrats cheered the Mexican president for his criticism of the controversial Arizona immigration law, while Republicans afterward lectured Calderon on the imprudence of knocking the host.
But that wasn't the only area where the two parties had completely different reactions.
At several other points in the speech, Democrats egged on Calderon as he pressed for U.S. policy changes and trumpeted developments in his own country.
Democrats rose to their feet, and Republicans stuck to their chairs, when Calderon called on Congress to consider reinstating the assault weapons ban, when he talked about his country's "universal" health care program, and when he pledged to fight for immigrants' rights in the United States.
The dynamic suggests U.S. interaction with Mexico could become politically tricky.
When Calderon took several minutes last Thursday to discuss the problem of assault weapons crossing the border into Mexico, Democrats visibly aligned themselves with Calderon's message.
"With all due respect, if you do not regulate the sale of these weapons in the right way, nothing guarantees that criminals here in the United States with access to the same power of weapons will not (decide) to challenge American authorities and civilians," he said, while being careful to cite his "respect" for the Second Amendment and the "political sensitivity" of the issue.
But he criticized the abundance of gun shops along the U.S.-Mexico border and called for Congress to act.
"I will ask Congress to help us, with respect, and to understand how important it is for us that you enforce current laws to stem the supply of these weapons to criminals and consider reinstating the assault-weapons ban," Calderon said.
Congressional Democrats -- including House Majority Leader Steny Hoyer and Majority Whip James Clyburn -- gave a standing ovation, while Republicans did not budge.
Later on in the speech, Calderon said Mexico was on its way toward "a goal any nation would be proud of: universal health coverage by 2012."
Again, Democrats rose to their feet to applaud Calderon, while Republicans -- still bruised over the yearlong health care overhaul fight in Washington -- stayed put.
In another odd moment, rows of Democrats rose to applaud Calderon when he delivered a brief portion toward the end of his speech in Spanish. First in Spanish, then in English, Calderon voiced his respect for "migrants" who have left their families to work in the United States and pledged to work for their "rights."
Republicans remained seated while Democrats rose for extended applause. Neither side of the aisle had any reaction when Calderon restated the line in English.
The section of the speech that got the most attention was shortly after that, when Calderon criticized Arizona's immigration law after calling for comprehensive immigration reform.
"It is a law that not only ignores a reality that cannot be erased by decree but also introduces a terrible idea using racial profiling as a basis for law enforcement," he said.
Once again, Democrats rose to applaud while Republicans did nothing. After the speech, Republicans voiced disappointment in Calderon for using the floor to criticize American law.
"I'll tell you what's even more galling is to have members of the White House staff standing and applauding something that is absolutely wrong," Arizona House Speaker Kirk Adams told Fox News not long after the speech.