Now, I don't believe for a minute that no Democrats running for office in 2010 ever hired an illegal immigrant. But here's the beauty of the situation: An undocumented worker would not dare expose an elected Democrat.
Before the 2008 election, The Boston Globe tracked down the landscaping firm hired by Romney. Some of the workers apparently were illegal.
There's an impossible standard for non-politician candidates. Romney, it seems, was supposed to check the documents of people who worked for people who worked for him. Reporters seemed to think Whitman was supposed to suspect that Diaz, with her heavy accent, was illegal.
Romney has been running a smooth, professional campaign. When the primary is settled, however, this race will be an entirely different game. The personal attacks will be relentless.
Romney might not have a housekeeper, observed Dan Schnur, a former GOP political strategist and director of the Jesse M. Unruh Institute of Politics at the University of Southern California, but "they're going to come at him with a dozen laid-off factory workers."
If it's Romney vs. Obama, the race will teeter on how Romney is defined -- whether the public sees him as "a battled-tested private-sector jobs creator or an out-of-touch plutocrat layoff artist."
"Whoever wins that fight," quoth Schnur, "wins the election."