PHILADELPHIA (AP) — Congressional Republicans are hoping for a message of unity and focus from Donald Trump in his first appearance before them as president.

Trump was to speak Thursday to House and Senate GOP lawmakers at their annual policy retreat. Despite a rocky start to his administration, many lawmakers are optimistic about delivering change in a new era of GOP control over Washington.

They would like to see a Trump committed to their agenda and results, not a president who veers off course into conspiracy theories about voter fraud or who keeps litigating the size of his inaugural crowds.

Before Trump’s appearance, House Speaker Paul Ryan sketched out an ambitious agenda to lawmakers that includes sending Trump a health care repeal bill by March and a rewrite of tax laws by summer’s end.

Also in the first 200 days Congress intends to confront paying for Trump’s newly announced border wall, which Ryan confirmed could cost $8 billion to $14 billion, and will work on a public works bill that Trump requested be added to a crowded agenda.

“I’m just so excited we finally have a chance to do this because we have the House and the Senate and a president who is with us,” Ryan told MSNBC on Wednesday about plans to overhaul the tax system, eliminating what critics say are loopholes and lowering corporate rates to 20 percent or even the 15 percent sought by Trump.

“If you can clean up the cesspool of the tax code and give us a pro-growth tax code, that is how you grow the economy, that is how you take power and money out of Washington and give it back to the people,” he said.

Lawmakers were generally enthusiastic to see Trump take quick action on immigration, oil pipelines and other issues via executive order, even though they criticized Barack Obama for overusing such administrative tools when he was president. This time, Republican lawmakers justify it by saying Trump, in many cases, is undoing what Obama did.