What effect would Taney's decision have on the Republican's desire to limit the spread of slavery?

Taney's decision weakened the Republicans' wishes, making the Missouri Compromise unconstitutional and allowing slavery to expand.

Explanation:

Republicans took a stand against slavery and did not agree that slavery should be expanded to newly acquired states. In addition, they were in favor of the liberation of slaves, especially those who lived in states where slavery was prohibited. This position of the Republicans was strengthened when the Missori Commitment, which limited the expansion of slavery, was approved and when a slave named Dred Scott sued the government because he was kept as a slave even though he lived in a free state.

However, court president Roger B. Taney made two drastic decisions that strongly undermined republican ideals. That's because Taney said Missori's Commitment was unconstitutional, and he said that no slaves could sue the government. He made these decisions because when the federal constitution was created, slaves were not considered to be American citizens and without an inferior race and they should be kept submissive to white citizens. This prevented slaves from being able to prosecute anyone, as it allowed slaveholders to be able to promote slave activities anywhere in the country, since slavery was constitutional.