[citation needed] Vargas won a special election to the House of Representatives in 2017 upon the resignation of longtime incumbent Brian Dempsey.

He defeated school committeeman Paul Magliocchetti in the primary, and Republican nominee Shaun Toohey in the general election.

In 2021, Vargas announced that he would run for the State Senate the next year upon the retirement of incumbent Diana DiZoglio.

However, due to redistricting changing the district lines, Vargas withdrew his candidacy a few months later.

[citation needed] Vargas is a proponent of increasing the housing supply in Massachusetts.