WASHINGTON — Vice President Joe Biden warned of a gloomy four years for civil rights if he and President Barack Obama are not reelected, summing it up in ominous tones by uttering two words: Robert Bork.

Speaking to the NAACP at their convention Thursday, Biden asked delegates to close their eyes and picture an administration under Republican Mitt Romney — and then led them straight to the conservative jurist whose proposed appointment to the Supreme Court by then-President Reagan many of them fought to defeat.

Imagine the Supreme Court after four years of Romney appointments, Biden told the crowd.