LEAVENWORTH — Republican Kris Kobach settled speculation about the next phase of his career Monday by declaring his candidacy for the U.S. Senate with a message tethered to restraint of illegal immigration, a new era of government austerity and praise for President Donald Trump.

Kobach, still dealing with political fallout from losing the 2018 gubernatorial race to Democrat Laura Kelly, established a Kobach for Senate committee and divulged his plans to 100 supporters at a Leavenworth rally. He’s competing for the seat held by retiring Republican Sen. Pat Roberts.

“This is not a time for a quiet senator,” he said. “It’s not a time for a senator who wants to make everybody happy, doesn’t want to take a stand. It’s not a time for a senator who’s Republican-lite.”

Kobach said he would carry the flag in the Senate’s fight for more border wall and press to halt spending of tax dollars on undocumented migrants. He pledged to never vote for a tax increase and would oppose growth of the federal government. He promised to apply a constitutionalist’s defense to the right to carry firearms and limit abortion and to oppose the Affordable Care Act.

His entrance into the field elicited a swift reaction from Republicans, Democrats and potential rivals. He was reminded of both his loss last year in the statewide race for governor and his unsuccessful 2002 bid for U.S. House.

“Kris Kobach is pushing the same extreme, and often unconstitutional, policies he imposed as secretary of state,” said Vicki Hiatt, chair of the Kansas Democratic Party. “Kansans defeated Kobach twice before, and we’re confident Kobach will strike out in 2020.”

Kansas Senate Majority Leader Jim Denning, an Overland Park Republican, threw water on a Kobach candidacy.

“He will have a lot to prove to the Republican Party,” Denning said. “For one, he has to prove he is able to run a viable campaign. His 2018 gubernatorial campaign can be described as disorganized and amateurish at best. The Kansas GOP needs someone who can support and energize our party. Kobach had his shot, fell short and was handed defeat in the 2018 general election.”

No Democrat has won a U.S. Senate seat in Kansas since the 1930s, and the state has been captured by the GOP presidential nominee since the 1960s.

Kobach said Trump was “very encouraging” of his political aspirations when they spoke several days ago.

Kobach said much of the political establishment in Washington, D.C., would prefer Kansans elect a new senator who would quietly vote to expand government, decline to act on principle and do little to rock the boat. He said the nation would be in a “downward spiral” if not for Trump’s election because Democrats were aggressively pushing a socialist agenda.

“Our national sovereignty is at stake. Our constitution is at stake. Our economy is at stake. Our families are stake,” he said. “That’s why I’ve decided to launch this campaign. I will help the president make America great again.”

Jack Pandol, spokesman for the Senate Leadership Fund, said the imperative was to elect a Kansas Republican to follow Roberts and pointed to Kobach’s loss in the governor’s race. He said Kansans deserved a Senate nominee who could be victorious in the statewide contest and help prevent the Senate from falling into hands of Democrats.

Kobach, a rural Lecompton resident and two-term Kansas secretary of state, could find himself in a crowded primary in August 2020. He narrowly won the gubernatorial primary last year against Gov. Jeff Colyer, but sealed defeat in the general election by failing to broaden his political appeal.

Kobach recently sought a White House staff job tied to national immigration policy under Trump, who endorsed his candidacy for governor.