There is little doubt that political satire has changed the game for Saturday Night Live this season -- as this fall’s inspired skewering of the presidential candidates makes the 33-year-old late night comedy show seem more relevant than ever.

But Saturday Night Live also changed politics -- nailing politicians so mercilessly, or skewering issues so adeptly, they were forever changed in the public mind. As SNL expands the franchise through live, half-hour prime time bursts of the show’s political humor on Thursdays, starting tonight, a few examples of how SNL changed the game for politicians at key moments in the country’s history:

The impression: Chevy Chase’s take on a bumbling President Gerald Ford, inspired by Ford’s hitting his head while getting out of a helicopter, became the series’ first landmark impression -– though Chase looked and sounded nothing like the guy he was spoofing.

The impact: Besides crystallizing the most athletic president as a physical klutz, Chase’s Ford proved SNL’s political impressions were mostly about nailing the politician’s public image (see Dan Aykroyd as Richard Nixon and Jimmy Carter). Chase turned the public’s anger over a president who pardoned his impeached predecessor into a case for Ford as history’s biggest boob.

The impression: SNL’s take on the 1988 presidential debates, with Dana Carvey as a jittery George H.W. Bush and Jon Lovitz as a bad haircut-wearing, forklift-riding Michael Dukakis.

The impact: Blew up Dukakis as a height-challenged technocrat who couldn’t combat Bush’s blizzard of talking points. In one telling moment, Lovitz-as-Dukakis turns to the camera and says “I can’t believe I’m losing to this guy.” The real-life Dukakis went on to, indeed, lose to that guy.

The impression: SNL’s 2000 presidential debate satire, with Will Ferrell as George W. Bush and Darrell Hammond as Al Gore.

The impact: Both Ferrell and Hammond nailed their respective impressions, capturing Bush’s clueless verbal fumbling (coining the phrase “strategery”) and Gore’s awkward earnestness (mentioning a proposed Social Security “lockbox” about 30 times). But the sketch’s image of Gore as unlikably stiff was reportedly used by his own staff to loosen him up for future debates. Whether it worked is another debate.

Ferrell's Bush is here:

The impression: A February sketch with Fred Armisen as Barack Obama babied during a debate by fawning journalists, who shrugged off Amy Poehler’s Hillary Clinton.

The impact: The real-life Hillary Clinton referenced the sketch three days later during a real debate, saying “maybe we should ask Barack if he’s comfortable and wants another pillow.” Tougher press vetting of Obama followed, curiously enough.

The impression: Fey sums up Republican VP candidate Sarah Palin’s image as a foreign policy lightweight last month with the line, “I can see Russia from my house.”

The impact: At times, Palin seemed to embody Fey’s impression during last Thursday’s vice presidential debate, offering so many folksy phrases (“doggone it” and “you betcha” were faves) some critics noted Alaska’s governor sounded like an SNL skit yet to be written. Which may be the highest compliment yet for Fey and the show.