Hillary Clinton will announce her presidential campaign on Twitter, on Sunday, while traveling to Iowa, the first caucus state, the Guardian is reporting.

Clinton will announce on her Twitter account that she is running and will follow with a video and email statement.

The Guardian notes her announcement will overshadow the expected announcement in Florida, on Monday, of Senator Marco Rubio, a strong Republican contender.

The former First Lady becomes the first major Democratic candidate to announce. She is expected to face opposition from former Maryland governor Martin O’Malley and former Senator Jim Webb.

She is currently the bookmaker’s favorite to become the first woman president in history and the first spouse of a previous president to win the White House.

Clinton was recently the keynote speaker at our sister publication Irish America Magazine’s Hall of Fame.

At that event she made clear that she would be a contender for the White House and that she would be seeking the support of Irish Americans.

The Clinton campaign has especially targeted the key Catholic vote states such as Ohio and Pennsylvania and will be seeking Irish American support across the country.

Irish American Democrats are expected to organize events and fundraisers in the months ahead. The Clinton family work on the Northern Irish peace process has meant they enjoy strong support in the activist community.

The Guardian reports she is booked to fly to Iowa on Sunday a state where she has had political difficulties.

She lost it to Barack Obama in 20008 despite being heavy favorite just a few months before and even finished behind John Edwards there. She is expected to tour the state early next week.

A poll yesterday showed her neck and neck in the state with Rand Paul in a general election.

The campaign will be based in Brooklyn Heights, just over the Brooklyn Bridge from Manhattan.