Updated

First lady Laura Bush capped a day of appearances Sunday with Senate candidate John Thune and urged South Dakota voters to elect him and other Republicans on Tuesday.

"President Bush sends his very best regards to everyone, but he sends you a reminder as well," she told about 2,000 people at a rally. "As soon as this rally is over you've got to get back to work to elect John Thune your next senator."

The White House, mindful of the stakes in Tuesday's midterm elections, sent Mrs. Bush out to rally the troops in South Dakota and other key states on the final weekend of the campaign.

Democrats now hold a 50-49 edge, with one Democratic-leaning independent. The appearances by Mrs. Bush, who is known to prefer reading to politics, is a sign of how seriously the White House is taking Tuesday's midterm elections.

"It is so important to participate in the political process and to get out and vote, to call your friends and neighbors and get the message out," Mrs. Bush said.

Earlier in Dell Rapids, Mrs. Bush attended church with Thune, his wife Kimberley, and their two daughters. She greeted campaign volunteers on a visit to state Republican party headquarters.

Mrs. Bush and the Thunes dropped by the Grand Opera House, a historic coffee shop and theater in Dell Rapids.

Thune was personally recruited by Bush for the campaign and is challenging Democratic incumbent Tim Johnson.

After Mrs. Bush arrived in Dell Rapids, a group of cold but excited residents sang happy birthday to her. Other well-wishers held homemade signs and bouquets of birthday balloons. She turns 56 on Monday — and celebrates her 25th wedding anniversary on Election Day.

Later Sunday, she met up with the president, who returned to the state for another campaign appearance on Thune's behalf. Bush informed the raucous crowd that it would be Mrs. Bush's birthday the next day.

"I thought it would be wise to hook up with Laura the day before her birthday," Bush said, prompting a hearty rendition of "Happy Birthday" from the crowd.

Mrs. Bush began her campaign swing Friday in North Carolina and was in New Hampshire, Iowa and Minnesota on Saturday.

The president, at a campaign stop Sunday in Springfield, Ill., with GOP Rep. John Shimkus, said the congressman "drew the short straw" in not getting the first lady at the event.

Shimkus "really did want Laura as his speaker — wise man," the president said.