Question: Who were the leaders of the opposition of the political group that has a large number of Protestants?

Knowledge 1: Protestantism
Episcopalians and Presbyterians, as well as other WASPs, tend to be considerably wealthier and better educated (having graduate and post-graduate degrees per capita) than most other religious groups in United States, and are disproportionately represented in the upper reaches of American business, law and politics, especially the Republican Party. Numbers of the most wealthy and affluent American families as the Vanderbilts and the Astors, Rockefeller, Du Pont, Roosevelt, Forbes, Whitneys, the Morgans and Harrimans are Mainline Protestant families. [SEP] Knowledge 2: Republican Party (United States)
Founded in the Northern states in 1854 by anti-slavery activists, modernizers, ex Whigs and ex Free Soilers, the Republican Party quickly became the principal opposition to the dominant Democratic Party and the briefly popular Know Nothing Party. The main cause was opposition to the Kansas -- Nebraska Act, which repealed the Missouri Compromise by which slavery was kept out of Kansas. The Northern Republicans saw the expansion of slavery as a great evil. The first public meeting of the general ``anti-Nebraska ''movement where the name`` Republican'' was suggested for a new anti-slavery party was held on March 20, 1854, in a schoolhouse in Ripon, Wisconsin. The name was partly chosen to pay homage to Thomas Jefferson's Republican Party.
Knowledge 1: Protestantism
Episcopalians and Presbyterians, as well as other WASPs, tend to be considerably wealthier and better educated (having graduate and post-graduate degrees per capita) than most other religious groups in United States, and are disproportionately represented in the upper reaches of American business, law and politics, especially the Republican Party. Numbers of the most wealthy and affluent American families as the Vanderbilts and the Astors, Rockefeller, Du Pont, Roosevelt, Forbes, Whitneys, the Morgans and Harrimans are Mainline Protestant families. [SEP] Knowledge 2: Party leaders of the United States House of Representatives
The style and role of any minority leader is influenced by a variety of elements, including personality and contextual factors, such as the size and cohesion of the minority party, whether his or her party controls the White House, the general political climate in the House, and the controversy that is sometimes associated with the legislative agenda. Despite the variability of these factors, there are a number of institutional obligations associated with this position. Many of these assignments or roles are spelled out in the House rule book. Others have devolved upon the position in other ways. To be sure, the minority leader is provided with extra staff resources—beyond those accorded him or her as a Representative—to assist in carrying out diverse leadership functions. Worth emphasis is that there are limits on the institutional role of the minority leader, because the majority party exercises disproportionate influence over the agenda, partisan ratios on committees, staff resources, administrative operations, and the day-to-day schedule and management of floor activities.
Knowledge 1: Protestantism
Episcopalians and Presbyterians, as well as other WASPs, tend to be considerably wealthier and better educated (having graduate and post-graduate degrees per capita) than most other religious groups in United States, and are disproportionately represented in the upper reaches of American business, law and politics, especially the Republican Party. Numbers of the most wealthy and affluent American families as the Vanderbilts and the Astors, Rockefeller, Du Pont, Roosevelt, Forbes, Whitneys, the Morgans and Harrimans are Mainline Protestant families. [SEP] Knowledge 2: National American Woman Suffrage Association
When Catt again became president in 1915, the NAWSA adopted her plan to centralize the organization and work toward the suffrage amendment as its primary goal. This was done despite opposition from southern members who believed that a federal amendment would erode states' rights. With its large membership and the increasing number of women voters in states where suffrage had already been achieved, the NAWSA began to operate more as a political pressure group than an educational group. It won additional sympathy for the suffrage cause by actively cooperating with the war effort during World War I. On February 14, 1920, several months prior to the ratification of the Nineteenth Amendment, the NAWSA transformed itself into the League of Women Voters, which is still active.

Answer: anti-slavery activists, modernizers, ex Whigs and ex Free Soilers