While the Catholic Church never endorses candidates for political office, it does urge the faithful to pray for their elected officials.
Archbishop John Carroll set a standard in this regard, composing a "Prayer for our Government" in 1791.
Aleteia writer John Burger relates in an article how connected Carroll was to the founding of the United States:
John Carroll, born in Maryland in 1735, came from a Catholic family that had several members playing an instrumental role in early American history. His older brother Daniel Carroll II (1730–1796) signed both the “Articles of Confederation and Perpetual Union” (1778) and the Constitution of the United States (1787). His cousin Charles Carroll (1737–1832) was also an important member of the Revolutionary cause and was the last surviving signer of the Declaration of Independence (1776).
He was there at the beginning and sought to help the newly formed United States of America with his prayers.
Here is a short excerpt from his prayer that specifically references the president, asking God to inspire the president with the Holy Spirit:
We pray O God of might, wisdom and justice, through whom authority is rightly administered, laws are enacted, and judgment decreed, assist with your Holy Spirit of counsel and fortitude the president of these United States, that his administration may be conducted in righteousness and be eminently useful to your people over whom he presides; by encouraging due respect for virtue and religion; by a faithful execution of the laws in justice and mercy; and by restraining vice and immorality.