Lincoln was in Monmouth leading up to the state and federal elections of 1858. Lincoln was running against Stephen A. Douglas, the Democratic incumbent, in the 1858 Federal Election as the Illinois Republican Party’s candidate for the U.S. Senate. He traveled heavily during the summer and fall of 1858, crisscrossing Illinois delivering speeches and campaigning on behalf of Republican candidates for federal and state office. In addition to his individual engagements, Lincoln debated Douglas at seven locations around the state. At the time, the Illinois General Assembly elected the state’s representatives in the U.S. Senate; thus the outcome of the races for the Illinois House of Representatives and the Illinois Senate was highly relevant to the Lincoln’s candidacy. See the 1858 Illinois Republican Convention.

On July 2, the U.S. Senate brought the bill up to a vote and a debate on the bill ensued, during which Trumbull and others proposed multiple amendments. Douglas participated in this debate. Trumbull argued that because Toombs’s bill stipulated that the Kansas Territory’s voters be, in effect, re-registered under federal supervision, that the bill was asserting the right of the U.S. Congress to regulate and govern the territories and would therefore nullify laws which the Kansas Territorial Legislature had passed related to the management of its own elections. The Kansas-Nebraska Act did not specify that the U.S. Congress reserved the right to assert its authority over the territories’ elections. Although the Senate voted to amend the Toombs bill so that the Kansas Territory’s elections were merely postponed rather than forbidden until the “complete execution” of the act, Trumbull argued that the bill exposed Douglas and the Democrats’s hypocrisy on the concept of popular sovereignty. Trumbull proposed an amendment with language explicitly declaring “all the acts and proceedings” of the Kansas Territorial Legislature “null and void” as well as an amendment making it clear that the Kansas Territorial Legislature held the right “at any time to exclude slavery . . . or to recognize and regulate it therein.” The Senate rejected both of these amendments.

Toombs’s bill passed the Senate, which had a Democratic majority, on July 2, but ultimately failed in the U.S. House of Representatives, in which Republicans held a majority.

The Whig Party effectively came to an end in the first half of the 1850s as opposition to the Kansas-Nebraska Act fractured the Whig voter base into several new parties. The remaining political parties attempted to draw support from the former Whig voters in an attempt to absorb their numbers and secure political influence. Both Republican and Democratic candidates made attempts to portray themselves as the successors to the Whig party. Both Lincoln and Douglas compared themselves to Henry Clay, who was incredibly popular among the former Whig voter base. Douglas and Clay both worked on the Compromise of 1850, which temporarily lowered rising tensions over the expansion of slavery into states that were being admitted into the Union. Clay died in 1852. Douglas portrayed himself as the successor to Clay in the 1858 campaign, a portrayal that Lincoln refuted in his own speeches.

In the state’s local elections as a whole, Republicans won a majority of all votes cast in the state, but pro-Douglas Democrats retained control of the General Assembly and Douglas ultimately won reelection to the U.S. Senate. Through the campaign, however, and in particular through his participation in the Lincoln-Douglas Debates, Lincoln gained recognition as well as standing within the national Republican Party.