Clinton was in the opening sketch of the show in which she responded to a skit performed the previous week in which Amy Poehler played Clinton and Fred Armisen portrayed Sen. Barak Obama, D-Ill.
Clinton was joined by actress Amy Poehler for a discussion of fashion, giggles and other Clinton mannerisms that Poehler has adopted.
Clinton popped up unannounced, taking part in the follow-up skit to one last weekend mocking kid-glove treatment of her opponent Barack Obama.
Clinton's campaign has gotten a good deal of mileage out of the "SNL" sketch from a week ago.
At last week's debate with Obama, she brought up the parody that portrayed the media being hard on her and soft on Obama.
Campaigning in Texas Saturday, Clinton sharpened her criticism of Obama, saying, "His entire campaign is based on a speech he gave at an anti-war rally in 2002," in which he spoke out against an invasion of Iraq.
Clinton says it's an example of not following up on words with action.
Yesterday she kicked off a bus tour of Ohio counties, planning to visit 88 of them.
A new poll indicates Clinton is in a virtual tie with Obama in Ohio. She had held a substantial lead.
Texas, Vermont and Rhode Island also hold primaries Tuesday, which is seen as a pivotal day for Clinton.