Massachusetts Gov. Deval Patrick's (D) decision to name his former chief of staff, William "Mo" Cowan, as an interim replacement to outgoing Sen. John KerryJohn Forbes Kerry2020 Dem contenders travel to key primary states When it comes to Colombia, America is in a tough spot 36 people who could challenge Trump in 2020 MORE (D) came as a surprise to some — but it may have made the lives of both former Sen. Scott Brown (R) and Patrick himself a bit easier.

By choosing a friend and longtime supporter — and a man with a relatively low political profile in Massacusetts — Patrick avoided the potential bombast and bomb-throwing that might have occurred had he appointed former Rep. Barney Frank (D-Mass.), who had very publicly pursued the job. 

Frank is known as an outspoken lawmaker, and Patrick's preference for a low-key legislator trumped Frank's deep store of congressional connections and know-how. 

But Frank or Vicki Kennedy, the widow of the late Sen. Edward Kennedy (D), who been rumored for the interim position, might also have stolen the political spotlight in the state from the Democratic nominee in the coming June 25 special Senate election. 

At a press conference announcing Cowan's appointment, Patrick said he wasn't concerned that Massachusetts had seen some of its power in Washington diminish after losing two of the upper chamber's longest-serving senators — Kerry and Kennedy — over the past few years.

"I do get that part of clout in Washington is seniority. But I do think that one of the reasons why our delegation has consistently been so strong is because of the depth of the people we send, and Mo Cowan is very much in that tradition," he said.

Cowan becomes the second African American now in the Senate, following the appointment of Sen. Tim ScottTimothy (Tim) Eugene ScottAfter Florida school shooting, vows for change but no clear path forward GOP senator: FBI failure in Florida shooting 'a separate issue' from Russia probe Sunday shows preview: Russian charges, Florida shooting dominate coverage MORE (R-S.C.) in December. 

Some Republicans believe Cowan's appointment might also be a boon for Brown, the former GOP senator who lost his seat to Elizabeth WarrenElizabeth Ann WarrenTrump's SEC may negate investors' ability to fight securities fraud Schatz's ignorance of our Anglo-American legal heritage illustrates problem with government Dems ponder gender politics of 2020 nominee MORE (D), and is considering running in the special election. 

Massachusetts Republican strategist Rob Gray said Patrick, by not picking a better-known Massachusetts Democrat, denied his party an interim senator with the fundraising clout and stature to help the party's nominee in the special.  That may factor into Brown's decision on whether to run for the Senate seat. 

"Let's say Deval Patrick had put Vicki Kennedy in the seat, and she decided to play a role in the (special election) race through endorsements and political activity on behalf of the Democratic candidate. That would be a consideration for Brown," Gray said.

Vicki Kennedy endorsed Rep. Edward MarkeyEdward (Ed) John MarkeyRegulators seek to remove barriers to electric grid storage Markey, Paul want to know if new rules are helping opioid treatment Oil spill tax on oil companies reinstated as part of budget deal MORE's (D-Mass.) candidacy in the Senate special, but hasn't given any indication she'll campaign for him.

A position in the Senate, however, could have put Kennedy in close contact with Washington donors to help a Democratic candidate in the upcoming special.

Brown has not yet revealed whether he is planning to launch his third bid for Senate in as many years, though recent reports indicate he is gearing up for a run. Gray said he had likely not launched his bid because he was waiting for all the moving political pieces to fall into place.

"Why not wait until the Democratic field is settled, and the governor has made his temporary appointment, so that you know exactly what the playing field is going to look like?" Gray said.

The Democratic field for the special election, Gray argues, is looking increasingly favorable to Brown. 

With no outspoken, high-profile appointment to the Senate, and a Democratic primary between Markey and Rep. Stephen Lynch (D-Mass.) expected, Brown may see another shot at the Senate as an attractive proposition, he said.

Frank, meanwhile, did not want to discuss his personal feelings Wedneday about being passed over for the interim Senate seat. 

"If I wanted to talk about feelings, I would have called Oprah," Frank told The Hill. 

Frank, who served for three decades in the House, said he wasn't concerned that Massachusetts would lack seniority in the Senate with only freshman Warren and Cowan currently representing the state. 

He noted that the two senators "have a very good congressional delegation to work with."

Frank said that while he didn't know Cowan well, he was confident the new senator would support Obama's agenda. And his advice to the man who will take up the seat he pursued? Stand up against Republicans, and for entitlements.

"Substance is important. Increasing the debt limit is not a favor that the Republicans do for us. And particularly, the Republicans are every bit as responsible for the debt we have to pay as the Democrats, maybe even more so," Frank said.

"Cutting back on [Medicare and Medicaid] exacerbates inequality," he added.