WASHINGTON — The top five House Democrats are urging Speaker Paul D. Ryan to establish a select committee on “the rise of white supremacy and domestic terrorism.”

The lawmakers, in a letter sent on Wednesday to Mr. Ryan, argued that Congress needed to study an “outbreak of hate” brought on by last year’s presidential election, as well as the threat that white supremacist groups pose to “the security and stability of our nation.”

Representative Joseph Crowley of New York said he had broached the idea of the select committee after watching Mr. Trump praise the “very fine people on both sides” of the deadly violence at a rally of white supremacists in Virginia.

“A young woman lost her life as a result of what took place in Charlottesville,” Mr. Crowley said in an interview. “That cannot be understated, and that life ought to not go without recognition by the Congress.”