In many ways, U.S. Sen. Brian Schatz seems the opposite of the man he replaced, the late Sen. Daniel Inouye.

Beyond obvious demographic differences, Schatz is a more liberal Democrat than the iconic Inouye, more partisan and more media-aware.

He also has less job security; unlike Inouye’s nearly 50 years without a serious election challenge, Schatz fought for his life against Colleen Hanabusa in 2014 and is waiting to see if he’ll face another battle this year.

But when it comes to their styles of representing Hawaii in the Senate, Schatz shows similarities to Inouye.

Inouye’s power came partly from his seniority as the second longest-serving senator in history, and Schatz is quick to note that while much has changed in the Senate since Inouye’s heyday, the importance of seniority has not.

At 43, he vows to serve as long as voters let him, hoping to build the seniority that helped Inouye bring Hawaii so much federal bounty that he was considered his own leg of the local economy.

When Schatz, the former lieutenant governor, was appointed by Gov. Neil Abercrombie to replace Inouye, he was sworn in a few days ahead of the 2013 class that included Hawaii Sen. Mazie Hirono.

It gave him a critical seniority jump over other freshmen that he used to land seats on the Appropriations and Commerce committees, the same powerful panels Inouye operated from.

Inouye’s clout also derived from his respect for Senate traditions of collegiality, ability to form diverse friendships and willingness to do heavy legislative lifting out of the limelight.

Schatz followed the example by forming tight relationships with colleagues, keeping partisan fights from getting personal, and diving into committee work and policy details.

Colleagues seem eager to partner on his top legislative interests, which include preserving Social Security, reducing climate change and controlling college debt.

Sen. Charles Schumer of New York, likely the next Democratic leader, took an early liking to Schatz. The congressional watchdog Roll Call noticed when Schumer and high-profile Massachusetts Sen. Elizabeth Warren deferred to Schatz at an event promoting lower college costs.

That same week, Roll Call noted, Schatz worked with Sen. Sheldon Whitehouse of Rhode Island on a carbon tax bill and with Sens. Christopher S. Murphy of Connecticut and Martin Heinrich of New Mexico in an article advocating a new Marshall Plan abroad.

Roll Call described him as having “a rising profile on the left” and Whitehouse said Schatz “brings a combination of kindness and gravitas that makes him a valued asset to our (Democratic) caucus.”

After the Hanabusa scare, Schatz launched an aggressive fundraising campaign that put off even some supporters, but with $2.6 million in the bank and no declared opponent so far, his recent pitches have taken a more senatorial tone.

Reach David Shapiro at volcanicash@gmail.com or blog.volcanicash.net.