Sen. Thom Tillis (R-N.C.), center, speaks with Sen. Rick Scott (R-Fla.) before a Senate Armed Services subcommittee hearing. (J. Scott Applewhite/AP)
Opinion writer

The News & Observer in Raleigh, N.C., reports:

Sen. Thom Tillis has drawn a Republican challenger in 2020.

Garland Tucker III, the retired chairman and CEO of Triangle Capital Corporation and an author, filed paperwork with the Federal Election Committee to run in the Republican primary on Monday. Tucker wrote “Conservative Heroes: Fourteen Leaders Who Changed America — Jefferson to Reagan” and has served on the board of the John Locke Foundation and the Raleigh-based Civitas Institute.

Tillis (R-N.C.) infamously flip-flopped on the president’s phony emergency declaration — writing an op-ed in The Post in support of nullifying it and then reversing course to support the president’s naked power grab. Beyond that, Tillis has been among the many passive go-alongers in the GOP, voting to repeal the Affordable Care Act, voting for the unpopular tax plan that surely didn’t pay for itself and rubber-stamping a slew of nominees who were subsequently forced out for ethical problems or plain incompetence. He’s had a few moments of political independence — supporting a measure to protect the special counsel, favoring a more reasonable line on immigration — but never took action to force a showdown with the president, even when the president’s Trump’s actions harmed Tillis’s constituents. (Claw back trade authority to end the fruitless trade war? Nope.)

Tillis may now draw primary challengers from the right-wing of the GOP (e.g., rabid anti-immigrant advocates) as well as more moderate Republicans who challenge Trump’s disastrous foreign policy management, climate change denial and protectionism.

Should Tillis move right to secure a primary win, he’ll be left scrambling to return to the center for the general election. There he’ll face charges of flip-flopping and vilified for enabling an erratic, unfit president.

Tillis’s biggest problem will be running with Trump at the top of the ticket. Provided Democrats don’t blow it with a unelectable nominee, North Carolina will be a key battleground state and a place to re-energize African American voters. Like it or not, Tillis is going to be joined at the hip with Trump and held to account for failing to take on the latter’s racism, corruption and trade wars.

Vulnerable Senate Republicans (e.g., Sens. Joni Ernst of Iowa, Susan Collins of Maine, Cory Gardner of Colorado) should be on notice: They can never be loyal enough (e.g., Collins on health care) to prevent a Trumpian challenge but as they try to mollify the right (e.g., Gardner voting down the line on Trump’s agenda), they anger moderates in their states who helped elect them. (Collins’s poll numbers have sunk since her vote to confirm Justice Brett M. Kavanaugh.) They’ve tried to have it every which way and wind up pleasing no one while enraging Democrats.

Instead of doing everything in their power to check Trump’s excesses and/or make a second term untenable, they’ve paved the way for a nominee at the top of the ticket who’s likely to drag them under.

The smart play for Sens. Tillis, Ernst, Collins and Gardner would be to back efforts to enforce subpoenas against Trump and his cronies, demand production of Trump’s tax returns and insist on divestiture of his businesses. In other words, the more pressure they can put on Trump not to run again or to encourage a viable challenger, the better. The more they are seen as fighting against power grabs, the easier to separate themselves from a toxic president.

In sum, the best way for Senate Republicans to hold onto their seats is to chase Trump from the race or at least be seen as willing to take on his most disagreeable views, rhetoric and policies. Trying to mollify him while periodically acting on principle doesn’t seem like a winning strategy.

Read more:

Thom Tillis: I support Trump’s vision on border security. But I would vote against the emergency.

Max Boot: The GOP’s declaration of moral bankruptcy

Paul Waldman: No bottom: Republicans show they’ll defend just about anything Trump does

Max Boot: Joe Biden is wrong about the GOP — but in the right way

Jennifer Rubin: The GOP is silent and spineless as Trump attacks a war hero