The short answer: Yes, the Ku Klux Klan certainly targeted the white enemies of white supremacy and southern racial order.

  I don't know of any exact numbers, so I cannot say whether or not over 1,000 white Republicans were killed the the KKK - it would help to know what time frame this person was talking about. Do they mean white Republicans targeted from the KKK's founding to the end of Reconstruction (about a decade), or from the KKK's founding on-wards (about 1/3 of the 19th century, and over a century today)?

  Regardless, I'll expand on my short answer here. The Republican party of the 19th century, contrasting with the Republican party of the 21st century, had virtually no political power in the American South. The States that would comprise the Confederacy were solidly in the Democratic Party, and the Republican Party, a newcomer on the stage of American politics, found its base in the Northern, industrial states rather than the agrarian south.

  By the time of the election of 1860, “virtually everyone in the South put the racial threat to white men’s exclusive citizenship front and center in the campaign. From state and local meetings all over the South a chorus of charges erupted that Lincoln had been elected by black men’s votes and that the Republican Party was advancing a racial agenda of abolition and racial equality. All believed that slavery, the bulwark of the white man’s republic, was under direct assault” (McCurry, 21). While Lincoln and the more moderate base of the Republican Party were initially conciliatory towards slavery as it already existed in Southern states, the radical wing of the Republican Party, led by Congressman Thaddeus Stevens and Senator Charles Sumner, dedicated themselves to eradicating slavery even before the Civil War. After the war, during the period of Reconstruction (~1865-1877), radical Republicans were the most vocal advocates for ensuring the civil rights of African-Americans. Their agenda can be described as one of "racial equality under the law" (Savage, 103), and their attitude towards the vanquished South was uncompromising. When President Johnson sought a more conciliatory approach, Stevens, arguing for a more punitive form of reconstruction, suggested the rebel states be treated as conquered territories, and that "proud, bloated, and defiant rebels" should pay for their "unjust and wicked war" (Masur, 81).

  Defeated militarily, the majority of Southern whites sought to maintain African-Americans as a permanent underclass. States such as Mississippi and South Carolina passed "black codes" to discriminate against freedmen. This prompted Republicans in Congress to pass a civil rights bill defining all people born in the United States as citizens, guaranteeing them “full and equal benefit of all laws and proceedings for the Security of person and property.” Despite Johnson’s veto, the bill passed, and Congress drafted the 14th Amendment to further protect civil rights, with Section 1 stating that no state law “shall abridge the privileges or immunities of citizens,” or deny any person “equal protection of the laws.” Every Republican in the house voted for the amendment, and every Democrat opposed it (Masur, 82).

  Around this time, the terms 'scalawag' (for Southerners supporting Republicans) and 'carpetbagger' (for Northerners coming south and helping freedmen and supporting Republican politics, or [alternatively] exploiting the chaos of the Southern economy following the war) entered public discourse as insults (Newman and Schmalbach, 296). The Ku Klux Klan, founded in June of 1866 as a private social club, quickly became an organization “whose members were rabid opponents of Republican politics and black equality… through the fall of 1868, they murdered white and black Republican leaders, terrorized the freedmen, and burned homes and schools” (Masur, 85)

  In 1870 and 1871, the Republican Congress under the Grant presidency passed the Enforcement Acts, meant to protect the political rights of African-Americans. The third act, known as the “Ku Klux Klan Act,” authorized the president to suspend habeas corpus if efforts to suppress the Klan were ineffective. However, by this point, political reconstruction was on its way out. Most white Southerners doggedly resisted what they perceived as Northern political meddling, and most Northerners had become weary of a process fraught with conflict, and sought to heal the national division. Local authorities in the South rarely (if ever) tried to protect African-Americans from white terror, and so, “by 1875, nearly every state had shaken off Republican rule” and restored conservative Democratic leadership (Masur, 90).

  Reconstruction would fail to rebuild the South as the radical Republicans imagined. Radical Republicans “proclaimed a new era of racial equality in law without building the psychological and social structures that could support equality” (Savage, 113).

 

  Sources:

Masur, Louis P. The Civil War: A Concise History. New York: Oxford University Press, 2011.

McCurry, Stephanie. Confederate Reckoning: Power and Politics in the Civil War South. Cambridge: Harvard University Press, 2010.

Newman, John J. and John M. Schmalbach. United States History: Preparing for the Advanced Placement Examination. New York: Amsco School Publications, 2006.

Savage, Kirk. Standing Soldiers, Kneeling Slaves: Race, War, and Monument in Nineteenth-Century America. Princeton, Princeton University Press, 1997.