President Donald Trump will travel to Mandan, North Dakota, on Wednesday to make his case for the need to reform the tax code, his second such trip in as many weeks.

In a surprise announcement late Tuesday afternoon, senior White House officials said Trump will be joined aboard Air Force One by North Dakota’s junior senator, Democrat Heidi Heitkamp, an unusual traveling companion for the Republican president. Also traveling with Trump will be the state’s GOP senator, John Hoeven, and Treasury Secretary Steven Mnuchin.

Trump’s remarks will include many of the same themes he addressed in a similar speech last week in Springfield, Missouri, according to White House officials. Chief among them, the need to cut the corporate tax rate, simplify the individual tax code and convince businesses to repatriate billions of dollars parked overseas.

Like his previous tax reform speech in Missouri, Trump will not offer any new details about the package of reforms currently being hammered out between administration officials and Republican leaders in Congress. Instead, said a White House official, “he’ll be talking about why tax reform is needed,” leaving the details up to congressional negotiators “out of respect for congressional order.”

Even without details, the White House said to expect a presidential road trip “almost every week” in the near term, offering Trump the chance to “get out and sell” tax reform.

On Wednesday, Trump will continue to hammer Democrats for “obstructing” American jobs, a line of attack he debuted last week in the home state of Democratic Senator Claire McCaskill, and a preview of the tone he intends to take during the 2018 campaign cycle.

“If Democrats continue their obstruction, if they don’t want to bring back your jobs, raise your pay and help America win, voters should deliver a clear message: do your job to deliver for America, or find a new job,” Trump will say, according to the White House, which released excerpts of the speech in advance.

But in a nod to Heitkamp, a vulnerable Democrat running for reelection, Trump will say that North Dakota’s energy boom, “is a reminder of what can happen when we promote American jobs instead of obstructing them.”

The White House said it was unclear whether Heitkamp would eventually endorse Trump’s tax reform plan once details of a reform bill are released. But her appearance fulfills a longstanding goal of the president’s to win bipartisan support, or the appearance of bipartisan support, for his legislative priorities.

It also signals that the Democratic bloc which successfully held together to oppose Trump’s Obamacare repeal may not be as ironclad on tax reform as it was on health care.

Heitkamp, however, is hardly a typical Democrat. Elected in a state that Trump won by 36 percentage points in the 2016 general election, Heitkamp is considered one of the Senate’s most vulnerable Democrats going into next year’s midterms.