The small Texan city of San Angelo has been turned upside down by one of the most unusual sex scandals ever to impact on American political life.

Joseph Lown, the popular mayor, suddenly resigned last week after revealing he had fallen madly in love with an illegal immigrant. That was the first revelation; the second was that his new partner was another man.

Not surprisingly the news has become the talk of Texas. In the socially conservative and solidly Republican state, gay marriage and illegal immigration are probably the two hottest potatoes in town.

Perhaps, then, it was no wonder that Lown announced the end of his career from Mexico, where he had fled with his new boyfriend and from where he could mourn the end of an otherwise successful political career.

The news came as a bombshell. Lown, 32, had just won a fourth term with 89 per cent of the vote. He was immensely popular after having worked long hours to fix the city's infrastructure and attending hundreds of community meetings.

He sent a text message to a city official hours before a ceremony to swear him back into office, saying he was in Mexico City with the man he loved, and would not be coming back any time soon. Not surprisingly, some local commentators greeted the news with a degree of hyperbole.

"It was, simply put, the most stunning abdication since Edward VIII gave up the British throne for Wallis Simpson in 1936," declared Rick Casey of the Houston Chronicle.

It left San Angelo officials bemused. At a hastily called press conference they were at pains to point out that Lown had left not because his partner was a man, but because he was illegal. Lown's decision to resign, they said, had been taken because no mayor could be seen to be aiding and abetting someone who had broken the law. "He hopes that the people of San Angelo will respect his decision," said Ty Meighan, the city council spokesman.

Despite the image of Texas as firmly in the anti-gay bible belt, there is a strong chance of that happening. The demographic nature of Texas has changed in recent years. Houston, Dallas and Austin all have gay communities. Dallas has an image as the "gay cowboy capital" of America.

In a press conference from Mexico, Lown said he had received hundreds of messages of support. He had replied to more than 300 of them. The couple would apply for legal residency for his boyfriend, although he admitted that could take years. Observer