WASHINGTON (CNN) -- Sen. John McCain was at the White House on Wednesday to get President Bush's endorsement for president, an event that has both Republicans and their Democratic opponents excited.

McCain clinched the GOP presidential nomination with victories Tuesday in Ohio, Texas, Vermont and Rhode Island, earning the nod from the current office holder.

"Everyone saw the calendar and did the math. It was obvious this would be a logical time" for the endorsement, a senior Bush administration official said of Wednesday's meeting.

McCain needed 1,191 delegates to secure the nomination and had 1,226 after Tuesday's voting, according to CNN estimates.

Republican Sen. Kay Bailey Hutchison of Texas said McCain can now focus on solidifying support among conservative Republicans, the majority of whom backed candidates other than the Arizona lawmaker in the primaries, according to exit polls.

"I think the endorsement of President Bush will certainly go a long ways toward that," Hutchison said Wednesday. "John McCain is going to be very focused on our base and the people that he wants to have in full force behind him."

Despite overall approval ratings hovering just above 30 percent, Bush receives far higher marks from conservatives, and the McCain campaign thinks the push from Bush will bring the party in line behind their presumptive nominee.

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