WASHINGTON — Departing Sen. Mark Kirk, R-Ill., who blasted President-elect Donald Trump during his campaign, praised Trump’s national security picks when we talked on Monday, in a conversation reflecting on Kirk’s years on Capitol Hill.

Kirk seemed open to an overture from Trump, if Trump wanted to make use of his extensive national security expertise.

Kirk was defeated in November by Rep. Tammy Duckworth, D-Ill., who will be sworn in on Jan. 3. Kirk was an underdog from the start. Everyone predicted he would lose his bid for a second term in heavily Democratic Illinois — and he did.

“Hey Lynn, it’s the former Mark Kirk here,” he quipped when we started our phone conversation. He is not sure what is next. For now, he will split his time with his longtime girlfriend, Dodie McCracken, between his home in Highland Park and his apartment in Washington.

OPINION

First elected to the House in 2000, and to the Senate in 2010, Kirk is wrapping up a congressional career launched in 1984 as a staffer for former Rep. John Porter, R-Ill.

Overlapping most of that time was his service as a U.S. Navy reservist.

“It’s liberating, in a way,” Kirk said. He is looking for a spot with a firm — not to do lobbying — and some boards.

Kirk was out of the Senate for almost a year after a massive stroke hit on Jan. 21, 2012. He wants to volunteer to help fellow stroke victims in Illinois to tell them, “your worst days are not ahead of you. There are better days.”

He is committed to his annual Willis Tower stair climb to benefit the Rehabilitation Institute of Chicago.

Here’s what else we talked about:

ON TRUMP: Kirk was one of the most outfront Republicans in scorching Trump. He yanked his support for Trump last June and eventually urged him to just quit his bid.

Nonetheless, “I like the national security team that has formally been announced,” Kirk said. He was “very happy” with Trump’s intent to nominate retired Marine Gen. James Mattis to be Defense secretary and his pick of retired Lt. Gen. Mike Flynn for his national security adviser.

While Mattis has gotten an upbeat reception, Flynn’s trafficking in conspiracy theories has made him controversial. Kirk knows them both.

He praised Mattis as a “warrior scholar, someone who thinks things through before acting.”

After President Barack Obama fired Flynn in 2014, Kirk revealed that he offered Flynn a job on his Senate staff, based on their shared strong views on national security.

Flynn is someone who can say to Trump, “Mr. President, your national security policy here is not working on the battlefield. He is capable of doing that and that is why I like him so much.”

Since Trump flirted with staunch critic Mitt Romney for the secretary of State post, I asked Kirk, who carved out a reputation as a security hawk, staunch ally of Israel, and a specialist in terrorism and terrorism financing, who fought the Iran nuclear deal, if he would serve in a Trump administration.

“I always hoped that I could serve in a higher capacity in the national security architecture of the United States, after 23 years in the Navy. . . . I assume since I was so critical of the [incoming] administration there might not be an offer there,” Kirk said.

BIGGEST LEGACY ITEM: Kirk played a key role in nurturing the Captain James A. Lovell Federal Health Care Center in North Chicago, at Naval Station Great Lakes. In a time of VA scandals, Kirk said Lovell was “one of the best” in the country.

BIGGEST REGRET: Not being able to complete a federal ban on sewage dumping in the Great Lakes. He passed a law mandating new prior public notice of dumping. He plans on “watching very carefully” to make sure the EPA enforces his law.

THE LOSS OF THE MODERATE MIDDLE: Kirk was a proud moderate who was eager to work with Democrats on gun control, gay rights and other social and business issues.

Said Kirk, “I despair now,” having lost this election, “there is less of a role for Illinois moderates.”