Actually, I'm not sure what this law would change on this side of the ocean, given the precedents of Clinton v. Jones. But it's monstrous for Italy:
Italy's lower house of parliament has passed a bill that will grant immunity to Premier Silvio Berlusconi, who has had his share of run-ins with the law over corruption allegations in connection with his media empire… The bill gives legal immunity from prosecution to the president, prime minister and the speakers of the two chambers of parliament while in office, and is now expected to become law in record time when it advances to the Senate in late July.
Judges and much of Italy's left-wing opposition opposed the law, which will suspend any statute of limitations to a case until the defendant leaves office.
Italy, of all places, is a bizzare home for this kind of law. Until Berlusconi it was odd for a prime minister to last more than a year in office, but the country's frequent governing spasms didn't prevent it from growing wealthier and more prosperous at basically the rate you would have expected it to.