House Budget Committee chairman Paul Ryan, R-Wisconsin, is the poster boy for the assault on Social Security, Medicare and Medicaid. His budget plan, which laid the groundwork for the undermining of those essential programs and their eventual privatization, speaked a national outcry earlier this year. A historically Republican Congressional seat in western New York fell to the Democrats in a special election that turned largely on the question of Ryan’s austerity agenda.

But could Ryan himself be beat in 2012?

It’s possible. His southeastern Wisconsin district has elected Democrats in the past. It voted for Barack Obama in 2008. And even after a Republican-friendly redistricting, it is still home to traditionally Democratic towns such as Racine, Kenosha and Janesville.

Ryan faces a determined challenger in Democrat Rob Zerban, a local elected official in Kenosha who has been running hard all year. And a new poll suggests that Zerban, who has made the defense of Social Security, Medicare and Medicaid the core theme of his campaign, poses a genuine threat to the Republican incumbent.

Pollster Paul Maslin writes, on the basis of his survey of 405 voters in Ryan’s district, that the fight over Social Security, Medicare and Medicaid has “weakened incumbent Paul Ryan, who used to enjoy electoral and image majorities well over 60%. Ryan’s favorable rating has declined to 54% positive, his job rating is 55% and his reelect is 54%—all this before the beginning of an active campaign against Ryan. When voters hear positive information about Rob Zerban and Paul Ryan, Ryan’s support weakens further to 52%. Rob Zerban’s description receives a better than 3 to 1 positive reaction.”

Maslin adds that: “after respondents hear one additional paragraph description linking Ryan to the Republican leadership in Congress and describing his authorship of the House budget plan, his support falls below 50% and his favorable rating becomes like Obama’s and Walker’s—dead even at 46% positive and 46% negative. And… Rob Zerban trails Ryan by only six points after this very brief exposition of Ryan’s signature idea, 49-43%, with undecideds holding nearly unanimously negative views of Congress in general and more than 80% saying they have either a negative or neutral feeling toward Ryan at the end of the poll.”

Zerban, a Kenosha County supervisor, says: “This poll reflects what I knew in my heart—Paul Ryan will lose this race because he has failed this district and this nation in Congress.”

Zerban still faces a tough race. The political dynamics of 2012 are still being defined, in Ryan’s district and across the country. Ryan’s a serious and able campaigner. And he will have all the money that Wall Street can give. But it may just be that there is not enough money to defend the indefensible.