WASHINGTON — Candidates can forget lingering in cozy coffee shops to woo a table of undecided voters, or spending an icy afternoon ringing doorbells in some small-state suburb. The presidential campaign is going national now.
That means counting and wooing delegates to the two parties' national conventions, raising money in Manhattan and other big venues to pay for costly TV ads and aiming speeches and commercials at audiences from coast to coast.
"It's about arithmetic now, not just psychology," said John J. Pitney Jr., a professor of government at Claremont McKenna College in California.
Psychology still matters a bit, however, particularly on the Republican side. The next GOP contest is in Michigan on Tuesday, and if former Massachusetts Gov. Mitt Romney stumbles badly in the state his father once governed, it could be hard for him to recover.
"He has to win," said Douglas Koopman, a professor of political science at Calvin College in Grand Rapids, Mich.
But even if Romney gets his first major victory of 2008, his gaze will be on the states beyond, just as it will be for the Democrats.
The reason is in the numbers. To win the Democratic nomination, a candidate needs 2,205 of the party's 4,409 delegates. To win the GOP nod, a candidate needs 1,191 of 2,380.
Few of those delegates have been selected yet, but the process is poised to go from first to fifth gear.
It's a process that's complex and often varies from state to state, but the key numbers are these: On Feb. 5, 24 states and American Samoa will choose 1,681 Democratic and 975 Republican delegates.
California alone will get 173 GOP delegates. The winner of each congressional district in California will get all that district's delegates. Another 11 will be given to the statewide winner, and three more will go to the convention not pledged to any candidate.
That's one of the simpler systems. Iowa, which on Jan. 3 held the nation's first caucuses, doesn't select Republican delegates until June. Even then, none of those delegates is obligated to vote for anyone; they have until the night of the convention balloting in early September to decide whom to support
Democrats have their own quirks. The party has 796 "super-delegates" who aren't linked to any primary or caucus outcome. These are party officials, including Democratic National Committee members, members of Congress, governors and "distinguished party leaders," such as former Presidents Carter and Clinton.
Democrats also generally have a 15 percent rule, meaning that if a candidate fails to get that percentage, her or she gets no delegates.
The complicated systems explain why money and organization are now crucial.
After New York Sen. Hillary Clinton won New Hampshire's primary on Tuesday, her campaign chairman, Terry McAuliffe, boasted the next day that her treasury had swelled by $1.1 million in the hours after her victory speech.
Meanwhile, her chief rival for the nomination, Illinois Sen. Barack Obama, went to the Grand Hyatt hotel in New York City on Wednesday and raised an estimated $700,000.
Among Republicans, New Hampshire winner John McCain reported taking in $1 million as he surged to the top in the state. Runner-up Romney headed for Boston on Wednesday, had 500 volunteers make phone calls for funds and raised $5 million.
Because Feb. 5 is so delegate-rich, candidates are expected to find they can't afford to camp out only in South Carolina — where Republicans vote on Jan. 19 and Democrats on Jan. 26 — or Nevada, where both parties will hold caucuses on Jan. 19.
Certainly there will be retail campaigning in those places; Romney, McCain and former Arkansas Gov. Mike Huckabee plan to spend the next four days in Michigan, barnstorming the state before the Tuesday primary.
"South Carolina and Nevada are important, but they're not going to be knockout states," said John Fortier, a senior fellow at Washington's American Enterprise Institute, a conservative policy institute.
Instead, they're momentum-builders, ways of getting a day or two of favorable publicity and fresh ammunition to attract potential donors.
But unlike 2004, when Massachusetts Sen. John Kerry, who endorsed Obama on Thursday, won Iowa and New Hampshire and locked up the nomination, "psychology this year will not determine the outcome," Pitney said.
Numbers will, and that's why the candidates are looking beyond Detroit and Charleston, S.C., and Las Vegas. It's why Romney gave a speech at the Detroit Economic Club Thursday that could have been given anywhere, going on at length about fair trade, the savings rate and tax policy. It's why Obama on Wednesday went to Jersey City, N.J., a Feb. 5 state, for a rally and Clinton went home to New York, didn't campaign but sent out a fundraising e-mail.
"You have to be much more calculated in your strategy," said Wayne Lesperance, an associate professor of political science at New England College in Henniker, N.H. "It's a whole new ballgame. It's important to win."