U.S. Rep. Walker, R-6th, Won't Challenge Sen. Thom Tillis

U.S. Rep. Mark Walker announced Thursday that he won't challenge Sen. Thom Tillis in North Carolina's Republican primary next year, a move that reflects a state political environment where a candidate's support for President Donald Trump can help make or break a campaign.

Walker said he'll focus on remaining in the House, rather than trying to move over to the Senate, even after some state Republicans publicly had urged him on to take on Tillis. Walker also said he talked with Trump about a run.

Walker, who chairs the conservative Republican Study Committee, is now in his third term representing a central North Carolina district anchored in and around Greensboro.

"After prayerful reflection and consideration, I am confident that my continued service in the House will best help our efforts to reclaim the majority from Nancy Pelosi and advance our shared conservative goals," Walker said in Thursday's statement.

While Tillis already faces a GOP challenger next March in retired Raleigh financier Garland Tucker, Walker's entry would have pitted two Republican rising stars in Washington against one another in a massively expensive primary. Some Republicans worry a blistering primary in a battleground state could weaken general election efforts to keep the Senate and White House in Republican hands.

Walker told reporters at last weekend's state GOP convention that he had talked with Trump in the Oval Office about a run. Trump had not taken a public stand in the primary, however.

"The support from President Trump and conservatives across North Carolina in encouraging me to run for the Senate has been deeply humbling," Walker said Thursday, but the most important thing is to "keep North Carolina red for President Trump."

Walker's name surfaced as GOP activists complained Tillis hadn't supported Trump enough. Some were particularly unhappy with Tillis' initial opposition to Trump's emergency declaration for a U.S.-Mexico border wall. But Tillis later changed his mind and voted to support the declaration. Tillis said he did so after the president acknowledged to him some changes were needed to emergency powers laws.

Tillis has since intensified his public support for the president. In recent weeks, his campaign has highlighted his endorsement by South Carolina Sen. Lindsey Graham, one of Trump's closest Capitol allies. A video shows Graham praising Tillis for his role defending Supreme Court Justice Brett Kavanaugh during his confirmation hearing in the fall.

Vice President Mike Pence and Tillis were featured guests last month at a Greensboro fundraiser that was publicized as a Trump-Pence re-election event. Guests also gave to the Tillis campaign.

Tillis, a former state House speaker, narrowly upset Democratic Sen. Kay Hagan in 2014 after a GOP primary where several opponents questioned his conservative credentials. Tucker, a first-time candidate known previously for making campaign donations, is leveling similar criticisms, with a focus on Tillis' differences with Trump.

In a recent interview, Tillis said his voting record in support of Trump and his policies ranked near the top of Republicans in the state's congressional delegation. Still, Tillis' office routinely promotes his bipartisan legislation — a reflection of the needle he must thread in a closely divided state.

National Democrats have yet to put forward a high-profile candidate of their own in a state where Trump edged Hillary Clinton in 2016 by almost 4 percentage points. State Sen. Erica Smith and Mecklenburg County Commissioner Trevor Fuller have announced they're running.

Walker, a former Baptist pastor, took some heat this spring after the federal indictment of a North Carolina mega-donor accused of trying to bribe the state's insurance commissioner. Campaign finance records show Greg Lindberg also gave generously to Walker's campaign. Through a spokesman, Walker has denied any wrongdoing and said he cooperated with federal authorities.