Bob Corker's statement announcing his retirement included an eye-opening promise about his final months

In a statement announcing on Tuesday his intention to retire from the Senate after 2018, Sen. Bob Corker offered a rhetorical flourish that could hint as his intentions during his final year in office.

"I also believe the most important public service I have to offer our country could well occur over the next 15 months, and I want to be able to do that as thoughtfully and independently as I did the first 10 years and nine months of my Senate career," Corker said.

The outgoing Tennessee senator has been a fairly consistent supporter of the president throughout his time in office, but has a slightly lower rate of support than some of his colleagues.

According to data website FiveThirtyEight, Corker has voted with President Donald Trump's priorities 87.5% of the time, making him the fifth least likely Republican in the Senate to back Trump on the pieces of legislation put forward.

He bucked Trump earlier this year by voting against raising the debt limit in a package tied to extending government funding and providing money for Hurricane Harvey recovery efforts, and joined colleagues supporting sanctions on Russia.

The chairman of the Senate Foreign Relations Committee is leaving the Senate despite urges from Republican leaders like Senate Majority Leader Mitch McConnell to seek reelection.

Some, like former White House chief strategist Steve Bannon, amped up their search for a candidate to run to Corker's right, particularly following the Tennessee senator's criticism of Trump's comments about white-nationalist protesters in Charlottesville, Virginia last month.

Earlier polls indicating he may be vulnerable to a Republican primary challenger.