WASHINGTON — He has been accused of rigging the 2016 Democratic presidential primaries to thwart Bernie Sanders and facilitating a deluge of big money into politics. He helped arrange financing for the dossier of sometimes salacious and unverified claims about President Trump’s ties to Russia and now is under direct fire from the president, who has said he is trying to steal the Senate race in Florida from the Republican candidate, Gov. Rick Scott.

For an election lawyer, Marc E. Elias has drawn unusually intense attention and criticism.

But then, Mr. Elias, who is representing Senator Bill Nelson, the Democratic incumbent, in the Florida recount, has been at the center of an unusually large number of high-stakes political fights.

His role in the Florida battle, in which Mr. Scott’s lead has shrunk from nearly 60,000 votes at the end of election night to less than 13,000 votes out of more than eight million cast, has thrust him even further onto center stage as the Democrats’ lead lawyer and spokesman, making him a tempting foil for Mr. Trump.

Last week, Mr. Trump called him out by name, referring to “this guy Elias, who represented Hillary Clinton and a lot of very shady things.” That was an apparent reference to Mr. Elias’s secretly arranging funding from two of his clients — Mrs. Clinton’s presidential campaign and the Democratic National Committee — to compile research that became the dossier about Mr. Trump’s ties to Russia.