IF. Trump is impeached (indicted) by the House and acquitted by the Senate, then loses re-election, could the charges developed and explained by the House be used in federal court against ex-president Trump? Or does the Senate trial (of a sitting president) open the double jeopardy box?
Although I am not familiar with any case law on the subject, it appears the President, once impeached, can be tried in a criminal court based upon the same charges. The following provisions of the U.S. Constitution are relevant:
Article 1, Section 3
“Judgment in cases of impeachment shall not extend further than to removal from office, and disqualification to hold and enjoy any office of honor, trust or profit under the United States: but the party convicted shall nevertheless be liable and subject to indictment, trial, judgment and punishment, according to law.”
Article I
Amendment V
“No person shall be held to answer for a capital, or otherwise infamous crime, unless on a presentment or indictment of a grand jury, except in cases arising in the land or naval forces, or in the militia, when in actual service in time of war or public danger; nor shall any person be subject for the same offense to be twice put in jeopardy of life or limb; nor shall be compelled in any criminal case to be a witness against himself, nor be deprived of life, liberty, or property, without due process of law; nor shall private property be taken for public use, without just compensation.”
The Fifth Amendment states that no person be subject for the same offense to be twice put in jeopardy of life or limb; however, the Courts have extended the Fifth Amendment protections to all criminal procedure, regardless of the potential punishment. Here is a good article that breaks it all down:
“Although the text of the Fifth Amendment refers to being placed twice in jeopardy of "life or limb," the Supreme Court has said that protections against re-prosecution for the same crime extend to all felonies, misdemeanors and juvenile delinquency adjudications,
regardless of the potential punishment.”
Double Jeopardy - FindLaw
CONCLUSION: There is no conflict between the provisions of Article 1, Section 3, and the Fifth Amendment. Article 1, Section 3, clearly states the President may face criminal prosecution based upon the same charges. Double jeopardy does not attach because impeachment involves only removal from office and no criminal punishment.