U.S. House Speaker Nancy Pelosi, in a letter to President Donald Trump on Wednesday, suggested that the president’s annual speech before Congress be postponed or scrapped altogether in light of the legislative impasse that has led to the ongoing shutdown, the longest in U.S. history.

“Sadly, given the security concerns and unless government reopens this week,” the speaker wrote, “I suggest that we work together to determine another suitable date after government has reopened for this address or for you to consider delivering your State of the Union address in writing to the Congress on Jan. 29.”

Pelosi’s missive was cloaked in the politesse of a formal communication from the leader of one branch of government to another. But it was nothing less than a threat to deploy Pelosi’s authority as speaker to deny Trump the use of perhaps the country’s most powerful pulpit in the middle of a partisan standoff.

Without the speech, Trump would lose the single best opportunity a president gets each year to pitch his agenda both to Congress and the public, as well as to frame the national debate entirely on his terms.

Noting that a State of the Union speech has never taken place during a government shutdown, she cited the possible impact of the funding lapse on security preparations by the Department of Homeland Security and the Secret Service.

The State of the Union is annually designated as a “national special security event,” and as such, Pelosi wrote, requires “weeks of detailed planning with dozens of agencies working together to prepare for the safety of all participants.”

Presidents speak to Congress only by invitation and a joint resolution passed by the House and Senate. This is usually a formality, but if the 26-day shutdown continues, it won’t be this year.

Conceivably, Trump could simply choose another venue to deliver a State of the Union address, so long as he prints out a written copy and sends it to the Capitol. “He could make it from the Oval Office if he wants,” Pelosi told reporters.

With Democrats capturing control of the House of Representatives in midterms in November, Pelosi has reclaimed the mantle of Washington’s most powerful woman earlier this month — and an opposition scourge for President Trump.

The 78-year-old became the speaker of the House, a position she held for four years from 2007, when she made history as the first woman ever to rise to that post.

She served as the nation’s third-most senior official for years spanning the George W. Bush and Barack Obama administrations — and sealed her reputation as one of the great survivors in American politics.

In her first stint, Pelosi was a strong opposing force to Republican Bush in the final two years of his presidency. Her role as a check on Trump is similar.

She and the Democratic leadership have the power to block Republican legislation, hamstringing large parts of Trump’s agenda ranging from proposed new tax cuts to the construction of a wall on the border with Mexico.

And Pelosi could make life for Trump much harder if she launches impeachment proceedings.

So far she has spoken out against using such a powerful political cudgel against him, arguing that the explosive step would likely mobilize Republican voters eager to protect the president.

Earlier this month, Pelosi fired a warning shot at the White House, saying that impeachment proceedings are a possibility against Trump, depending on findings of the special counsel investigating Russia’s meddling in the 2016 election.

“We shouldn’t be impeaching for a political reason, and we shouldn’t avoid impeachment for a political reason,” she said during an appearance on NBC’s “Today” show.

Only the House can begin impeachment proceedings, and while Justice Department guidelines suggest a sitting president can’t be indicted, Pelosi called that “an open discussion.”

In her reprised role, she will have to thread a political needle, standing up to Trump when needed but also showing that her party is capable of working with the president to get laws passed.

“A Democratic Congress will work for solutions that bring us together, because we have all had enough of division,” Pelosi said.

The California Democrat has pledged to “reach across the aisle in this chamber and across the divisions in this great nation,” as the nation’s capital remained under the cloud of an ongoing government shutdown and deep divides weighed down her own party.

“The floor of this House must be America’s Town Hall: where the people will see our debates and where their voices will be heard and affect our decisions,” she added.

Pelosi’s fractured party and Republicans remain in a stalemate over taxpayer funding for the border wall President Trump used to promise Mexico would pay for.

With Trump in the Oval Office and a GOP-controlled Senate, Democrats don’t have much hope of passing any groundbreaking legislature. However, the party has vowed to use their newfound power in the House to provide oversight of the Trump administration and to investigate any wrongdoing on part of the president or his allies.

Pelosi is unquestionably among the savviest political leaders of her generation. She shepherded then-President Obama’s health-care law through the House to its contentious, historic passage in 2010.

Perhaps for that reason she is still seen by some as a liability eight years later, with Republicans presenting her as the ultimate liberal bogeywoman.

“Can you imagine Nancy Pelosi as speaker of the House?” Trump asked a crowd at a Minnesota rally last month.

“Don’t do that to me! I didn’t buy into that. Neither did you.”

Rep. Hakeem Jeffries, the Democratic Caucus Chair, heaped praise on Pelosi. “Nancy Pelosi is a woman of faith, a loving wife, a mother of five, a grandmother of nine, a sophisticated strategist, a legendary legislator, a voice for the voiceless, a defender of the disenfranchised,” he said.

Recent months have seen rising internal resistance from Democrats, with dozens of House Democrats and candidates signalling their desire for change at the top — including Tim Ryan, an Ohio congressman who challenged Pelosi for the leadership after the 2016 election but fell short.

“It’s not going to be a coronation,” Ryan said. “I think a lot of Democrats want a change.”

Young progressives like Rep. Alexandria Ocasio-Cortez — who became the youngest woman to serve in the House — have openly challenged several of Pelosi’s positions and could cause headaches for the centrist.

At the same time, Pelosi’s rise to regain power comes at a crucial time for women in politics. The 116th Congress counts an unprecedented number of women as members after 100 female lawmakers won elections this past November.

At least in part, Pelosi’s poor reputation is shaped by years of rightwing attacks. Conservatives depict her, the wife of an investment millionaire from California, as the embodiment of a leftist elite.

She is accused of everything from wanting to raise taxes for middle-class families to supporting a massive influx of illegal immigrants.

For three decades Pelosi has represented California’s 12th congressional district, which includes San Francisco, a stronghold of left-wing politics, counter-culture and gay rights regarded by many heartland conservative voters as a true Gomorrah.

Pelosi was born Nancy Patricia D’Alesandro in Baltimore to a political family with Italian roots. Both her father and brother were mayors of the East Coast port city.

After studying political science in Washington, she moved with her husband Paul Frank Pelosi to San Francisco, where they raised five children.

First elected to the U.S. House in 1987, Pelosi rose through the ranks to lead the chamber’s Democrats beginning in 2002, a position she still holds.

Pelosi, steeled by countless political struggles, has largely managed to hold her diverse caucus together.

U.S. politics requires donning “a suit of armor” and the ability “to take a punch,” she has said.(SD-Agencies)