PRAGUE  A popular online video here called “Convince Granny” urges young Czechs to withhold visits to their grandparents unless the old folks agree not to vote for leftist parties like the Communists in Saturday’s elections.

Modeled on the American comic Sarah Silverman’s video “The Great Schlep,” which in 2008 appealed to young Jewish voters to persuade their grandparents to support Barack Obama in the swing state of Florida, the Czech video is a testament to the Communist Party’s enduring influence here.

The creators of “Convince Granny” say they conceived the video, which has had more than 600,000 hits since it was posted on YouTube about a month ago, as a necessary weapon against the ascent of the unreconstructed Communist Party, which recent polls indicate could win up to 15 percent of the vote.

In addition to the jokes about Grandma’s selective memory, the video implores young viewers not to forget the insidious transgressions of the former Communist government, from the exile of the country’s leading intellectuals and artists to the execution of its political enemies.