He is now in a legal fight in his native Orange County, Calif., over a house he rented that the owners say he left looking like a pigsty, crawling with maggots.

There is a history of House members backing unpopular foreign leaders. In 2002, Representative Jim McDermott, Democrat of Washington, made a trip to Baghdad to defend Saddam Hussein’s record on international inspections and his dismantling of unconventional weapons. It earned him the nickname Baghdad Jim from many pro-war conservatives. Representative José E. Serrano, Democrat of New York, was such a consistent supporter of President Hugo Chávez of Venezuela that he posted on Twitter after the president’s death last year that Mr. Chávez was “committed to empowering the powerless.”

There is some logic to Mr. Rohrabacher’s stalwart defense of the Kremlin’s actions. The people of Crimea have spoken, he says, and voted resoundingly to leave Ukraine and join the Russian Federation. To stand for the sanctity of Ukraine’s national borders, he says, is to stand for “soil and entities” over individual rights and self-determination.

Was Abraham Lincoln wrong, then, to fight the Confederacy’s self-determination? Not at all, Mr. Rohrabacher said. Because women and blacks — slave or free — were not allowed to vote, Southern sentiment before the Civil War was not nearly as clear as it is in Crimea.

Sixteen other Republicans voted against the Ukraine aid bill on Thursday, but most — if not all — did so on fiscal grounds. They included the most vocal members of the Tea Party wing and the usual so-called Dr. Nos of the House, like Justin Amash of Michigan and Thomas Massie of Kentucky.

“Russia has violated Ukraine’s sovereignty; therefore, certain nonmilitary punitive measures against those responsible in Russia may be appropriate,” Mr. Amash explained on his Facebook page. “But I am not persuaded at this time that U.S.-guaranteed financial assistance for Ukraine’s interim government will produce good outcomes for the United States or Ukraine.”

It seems that defending the invasion of a sovereign nation and the annexation of part of it is a tough political position to hold. Senator Rand Paul, the libertarian-minded Republican from Kentucky who is considering a White House run, told The Washington Post in February that “some on our side are so stuck in the Cold War era that they want to tweak Russia all the time, and I don’t think that is a good idea.”