WASHINGTON (AP) — President Donald Trump has repeatedly said Canada should be the 51st U.S. state as he proposes to erase the 5,525-mile-long border that separates the two countries. The very notion is ludicrous to Canadians and the hurdles to transforming it into a state are sky high.

But in Trump’s thinking, the traditional Lower 48 states would become the contiguous 50 as the Canadian territory between the U.S. mainland and Alaska disappears, leaving Hawaii as the only non-continental state.

“If people wanted to play the game right, it would be 100% certain that they’d become a state,” Trump said recently.

Canada at first reacted as though Trump must be joking, and Prime Minister Justin Trudeau said flatly his country would never be the 51st state. Trudeau more recently suggested behind closed doors that Trump’s sustained annexation calls may not be just light talk and appear to be “a real thing.”

Here’s what it would take to transform Canada from a nation to a state:

What’s the process for add

ing a state?

Congress has to approve accepting a new state.

It takes only a House majority, but Senate filibuster rules require a minimum of 60 votes in the 100-member chamber to bring a bill to the floor — an insurmountable threshold for all kinds of key legislation.

The Constitution’s Admissions Clause, Article IV, Section 3, states: “New States may be admitted by the Congress into this Union; but no new State shall be formed or erected within the Jurisdiction of any other State; nor any State be formed by the Junction of two or more States, or Parts of States, without the Consent of the Legislatures of the States concerned as well as of the Congress.”

Any measure approving a new state that clears Congress would also have to be signed into law by the president. In the case of Canada, Trump has made it clear he would be eager to do so.

Republican Sen. Lindsey Graham of South Carolina, a Trump ally, joked on X when all 50 states certified Trump’s Electoral College victory last month, “They skipped Canada. We’ll fix that next time!”

No major legislation is advancing that would extend an invitation to statehood to America’s northern neighbor.

Doesn’t Canada have a say?

To say that most Canadian leaders aren’t interested in becoming a state would be an understatement. Ontario Premier Doug Ford, head of Canada’s most populous province, has spun out a counteroffer for Trump.

“How about, if we buy Alaska, and we’ll throw in Minnesota and Minneapolis at the same time,” he said, adding of Trump’s suggestion: “It’s not realistic.”

There have been multiple past pathways to statehood — from the absorption of the 13 colonies under the Articles of Confederation, to Congress formally agreeing to Texas’ request to be annexed as the 28th state.

Most states were added after Congress accepted a petition from some territorial legislative body, which could include legislatures that Congress itself suggested forming as part of the process.

Canada would probably have to have a referendum to gauge voters’ interests in joining the U.S. before more detailed aspects of the process could begin — and that’s almost certainly a non-starter.

While not addressing Canada as the 51st state directly, polling last year from Gallup and the Pew Research Center shows that Americans overwhelmingly have a positive view of Canada — and that while Canadians view the U.S. more positively than negatively, their view may be a little more muted.

Trump’s threats of tariffs have left Canadians feeling betrayed, and sports fans in Canada have begun voicing their displeasure by booing the U.S. national anthem at NBA and NHL games.

How would adding Canada affect U.S. elections?

Profoundly — and that’s without speculating about whether a majority of Canadians might back Democrats or Republicans for president and in Congress.

If Canada were to join the U.S. — again, a highly unlikely prospect — its population of 41.6 million would make it the largest state, outpacing California’s 39.4 million residents. Canada would get two senators but also 55 House seats based on the average congressional district population following the 2020 U.S. census, which was 761,169 individuals.

That would make Canada the presidential race’s richest prize, with 57 Electoral College delegates — exceeding California’s 54.

The Permanent Apportionment Act of 1929, meanwhile, caps the number of House seats at 435, meaning that other state delegations would have to shrink to make room for the new Canadian members of the House — and, by extension, its delegates to the Electoral College.

Suddenly, make-or-break swing states like Pennsylvania, Michigan and Wisconsin would not look so important if there were tens of millions of Canadians waiting to be wooed with a presidential election on the line.

What about other potential new states?

Before Trump took office for his second term, debate around adding State No. 51 traditionally centered around Puerto Rico and Washington, D.C.

Puerto Rico is a U.S. commonwealth, and its voters have approved statehood in nonbinding referendums. Proposals to allow it become a state have repeatedly been introduced in Congress but not approved.

Washington, D.C., residents have voted in support of statehood and approved a state constitution and proposed boundaries. A bill admitting into the union the city as Washington, Douglass Commonwealth, passed the Democratic-controlled House as recently as 2021 but not the Senate.

Republicans now control both chambers, meaning they’ll likely oppose adding states that could be majority Democratic like Puerto Rico or D.C.

The nation’s capital gets three Electoral College votes for president under the Constitution’s 23rd Amendment, though it lacks voting representation in Congress. That’s why the Electoral College has 538 total delegates: 435 House members, 100 senators and three for D.C.

When was the last time the United States added a state?

Hawaii became the 50th state in 1959, nearly 18 years after the Japanese bombed Pearl Harbor.

The island chain about 2,400 miles (3,900 kilometers) from the mainland United States was annexed as a U.S. territory by Congress in 1898. Many bills offering Hawaii statehood were subsequently introduced, but they stalled for decades amid racial discrimination and partisan disagreement.

By the early 1950s, Hawaii leaned Republican, and Democrats opposed its admission to the union without including Alaska, which was seen as more favorable to their party.

Alaska, separated from the mainland U.S. by about 500 miles (800 kilometers) of Canadian territory, was eventually admitted as State No. 49 in January 1959. That opened the door for Congress to approve Hawaii’s statehood that March, and Hawaiians voted to join the union on Aug. 21, 1959.

It turned out that Alaska has backed Republicans in every presidential election except 1964, while Hawaii has voted Democratic every presidential cycle but 1972 and 1984.