U.S. Republican presidential front-runner Donald Trump did a dramatic reading of the 1968 Al Wilson song "The Snake" at a rally Monday,  suggesting its story -- about a woman who takes in a half-frozen snake only for it to betray her -- was like the U.S. taking in immigrants.

Trump gave a dramatic reading of the 1968 song at his rally in Vienna, Ohio, on the eve of important primaries in five states.

"We have a tremendous problem with terrorism, and we have a tremendous problem where -- and I don't know if you agree with me -- but we cannot let people into our country that we don't know who they are, what they are doing, where they have no paperwork. We can't do it," Trump told supporters before reciting lyrics from "The Snake."

In the song, the woman nurses the snake back to health only to be bitten by the poisonous reptile, which will kill her.

2016-03-14T224056Z_2_MTZSAPEC3E1HR8AA_RTROPTP_3_USA-ELECTION-TRUMP Republican U.S. presidential candidate Donald Trump speaks during a town hall campaign event in Hickory, North Carolina March 14, 2016. Photo: REUTERS/Chris Keane

Trump can take a giant step on Tuesday (March 15) towards securing the Republican presidential nomination with wins in Florida and Ohio primaries on that would intensify the pressure on establishment Republicans fighting to derail him.

Trump has the potential for a sweep in five big states holding nominating contests for the Nov. 8 election - Florida, Ohio, Illinois, North Carolina and Missouri. He could potentially knock out two of his rivals, Ohio Governor John Kasich and U.S. Senator Marco Rubio of Florida, if he wins their states.

Trump has a significant lead over Rubio in opinion polls in Florida, but is neck and neck with Kasich in Ohio. Any win by either Rubio, Kasich or U.S. Senator Ted Cruz of Texas would give at least a small degree of hope to Republicans battling to deny Trump the nomination.