Massachusetts Gov. Deval Patrick, the nation’s only black governor, will give the keynote address at an Iowa Democratic Party dinner in June, fueling speculation that he is considering a presidential run in 2016.

The June 15 speech in Des Moines will be one of the first formal trips by Patrick to the state that traditionally starts the presidential process. His aides have downplayed the speech — one of his aides told the Boston Globe Patrick “has the only job in politics he wants, and that is serving as governor of Massachusetts.”

Patrick himself has also long said he has no ambitions for national office. The governor, a longtime Obama ally, has emphasized he is simply trying to help the president win reelection. Iowa is a key swing state where Obama won in 2008, but polls show a much tighter race this year.

And Patrick, as Mitt Romney’s successor in Massachusetts, appears on television frequently to attack the Republican presidential candidate, often highlighting how Romney’s stances now differ from those he took as governor.

At the same time, the presidential speculation is not totally unfounded. Patrick has said he will not run for a third term as governor in 2014, so he will leave office right as the 2016 presidential cycle starts.

And choosing to make a trip to Iowa, as Patrick and his advisers are no doubt aware, communicates its own message. Republicans and Democrats who eventually do run for president usually do make a stop in the state before they officially get in the race, testing the waters there first.

Patrick is one of a number of politicians who Democrats believe could run in 2016, with Hillary Clinton and New York Gov. Andrew Cuomo at the top of both lists.

Follow Perry Bacon Jr. on Twitter at @perrybaconjr