"The Tweed Ring was more than a Democratic Party scandal. William 'Boss' Tweed, leader of Tammany Hall — Manhattan's county Democratic organization — was chief architect of the scheme that embezzled millions of dollars of public funds between 1868 and 1871. Yet, Republicans also deserve a fair share of the blame... A clique of officeholders, the so-called Tammany Republicans, openly joined with the Tweed Ring during its climb to power. As early as 1868, newspapers reported 'a nice little arrangement.' The group was 'doing their best to defeat our Mayor and reelect the regular Tammany incumbent,' complained the New York Tribune. 'Perhaps this is the very way to promote Gen. Grant’s election. Do they expect to nominate him in Tammany Hall?'"
For more on Tammany Hall and the Tammany Republicans, check out this article by Jeff Broxmeyer in Gotham: A Blog for Scholars of New York City History.