WASHINGTON — Seeking to rally Republicans around a unified message on immigration ahead of the 2020 election, White House advisers Stephen Miller and Jared Kushner visited Capitol Hill Tuesday to brief Senate Republicans about the broad outlines of an immigration plan the two have drafted.

While details were sparse, the plan encompasses conservative ideas on border security and asylum seekers with some new proposals on legal legal immigration, according to senators who spoke after a weekly lunch where the briefing was given.

The new push comes as President Donald Trump, who built his 2016 candidacy on immigration and a promise to build a wall along the southern border, has struggled to obtain concrete results of his hard-line immigration policies in the first two-plus years of his presidency.

Immigration has dogged Congress for two decades, leaving some lawmakers skeptical that any plan offered by the administration could ever pass.

Still, some of the GOP senators said the plan is aimed more at rallying the party ahead of the 2020 election, not at gaining the support any legislation would need to pass the Democratic-controlled House.

“I don’t think it’s designed to get Democratic support as much as it is to unify the Republican Party around border security,” Sen. Lindsey Graham, R-S.C., said after the lunch.

The president and 18 Senate Republicans are running for re-election and those on the ballot are anxious to come up with an immigration policy they can coalesce behind in 2020.

The president has successfully made immigration central to his political identify. He ran his first presidential campaign on building a wall, paid for by Mexico. He implemented family separation at the border, rolled back parameters for asylum seekers and in the days leading up to the 2018 election, he elevated the caravan of Central Americans approaching the border.

He has a loyal following that supports his positions.

But he has had few policy successes. The wall has not been built and illegal immigration is increasing as the backlog of immigrants at the border increases. Additionally, a host of other immigration issues have gone unresolved, including the 11 million undocumented immigrants currently living in the United States and the DACA recipients who are now living in legal limbo.

Sen. Joni Ernst, R-Iowa, said she is generally supportive of the administration’s ideas, which have not yet been detailed into legislation or with many specifics.

“I think what was presented was a starting point for Republicans to say what we are for, not what we’re against. I think that’s really important is for all Americans to understand that we really are focused on immigration. We are ok with legal immigration and we need to modernize the way we do business,” Ernst, who is running for re-election next year, said.

A Republican strategist working closely on the 2020 down-ballot races in 2020 said that voters want elected officials to find solutions to problems plaguing the country and this is an effort to address those concerns.

“They’re trying to move the ball forward on certainly an important issue in the lead-up to the 2020 election for the president and senate Republicans,” said the strategist, who was not authorized to speak on the record.

And polling echoes that sentiment. An April NBC News/ Wall Street Journal poll found that immigration is one of the top issues voters think the government should address. And it’s the most important issue among Republicans, with 56 percent saying the government should address immigration and border security. (The second highest issue for Republicans was health care at 42 percent.)

Kushner and Miller’s ideas would change the Flores agreement to allow immigrant families to stay together in detention for longer than 20 days, allow non-Mexicans from being turned away at the border and allow people to apply for asylum from their home country.

It would also move legal immigration to a merit-based system, which would give preference to high-skilled, educated workers. It would, however, keep legal immigration levels the same, which is a compromise between the more conservative camp of Republicans who want to reduce legal immigration and those who are more supportive of legal immigration.

Sen. Graham, who is also up for re-election in 2020, is introducing his own immigration plan on Wednesday, and said he is likes that the White House is trying to be pro-active.

“We’re trying to present a plan that will unify Republicans. Whether it will or not, I don’t know,” Graham said.