Teachers’ union head Richard Iannuzzi praised Gillibrand’s “sterling record.”

Political observers generally poo-poo the practical significance of political endorsements, but New York Sen. Kirsten Gillibrand’s latest endorsement represents an exception to the rule.

Gillibrand on Monday landed the support of the New York State United Teachers union, an influential force in New York and particularly downstate politics, which will add heft and organizing ability to Gillibrand’s 2010 campaign as she prepares for what is likely to be a contested primary and general election.  

In a statement, NYSUT President Richard C. Iannuzzi said Gillibrand “has a sterling track record of commitment to strengthening education and health care, and will be the leader we need to ensure New York students have access to quality public education from pre-school through college.”