Alderman-at-large William A. White Jr., told The Somerville News he is considering a run for the state senate seat left vacant by the passing of Charles E. Shannon Jr., as a Republican.

White said he expects a special election to be called later this week with a primary in the middle of June and a final election in the middle of July.

His campaign would focus on three of Somerville’s priorities that must be addressed at the state level: the extension of the Green Line through the city, the creation of an Orange Line stop at Assembly Square and the increase in local aid funding, he said.

White said as the three-year chairman of the Board of Aldermen’s Finance Committee, he is uniquely qualified to make the city’s case on Beacon Hill.

In the state senate, his being a Republican is of almost no consequence. The Democratic Party’s dominance of the legislative branch is so broad, it does not matter if they lose or gain one seat in the senate, he said.

However, because it would greatly improve the political discourse statewide to have a Republican voice from an urban center.

In addition, he would have access to the Romney administration that the city needs to press its case, he said.

Shannon’s death was a shock to White, and so he has not completely worked out his campaign plans or even made his final decision, he said.

There are many factors involved, but White expects to make his decision within the next few weeks, he said.