Sen. Pat Toomey (R-Pa.) and Louisiana Gov. Bobby Jindal (R) are among the Republicans who threw their support to Mitt Romney immediately after Rick Santorum announced he was ending his presidential campaign. 

Sen. Lindsey GrahamLindsey GrahamSenate panel could pass new Russia sanctions this summer Overnight Cybersecurity: Bad Russian intel may have swayed Comey's handling of Clinton probe | Apple sees spike in data requests | More subpoenas for Flynn | DOJ's plan for data warrants Overnight Finance: GOP bill would leave 23M more uninsured, says CBO | Trump aides defend budget | Mnuchin asks for clean debt hike before August | Ryan says House could pass bill without border tax MORE (R-S.C.) and Florida Gov. Rick Scott (R) also endorsed Romney quickly after Santorum dropped out of the race. 

Iowa Gov. Terry Branstad (R) endorsed Romney just moments before Santorum’s announcement.

Both Jindal and Toomey urged Republicans to coalesce behind Romney, something some in the party’s base had been hesitant to do while a legitimate conservative alternative remained in the race.

"It’s time for all Republicans to focus their energies on the fall campaign which will give Americans a fundamental choice between [President] Obama’s lurch toward European style big government and the Republican alternative of a thriving private sector with a smaller government," said Jindal.

The Louisiana governor had endorsed Texas Gov. Rick Perry earlier in the cycle, but hadn’t backed a candidate since Perry’s withdrawal in January.

Despite the continued presence of Ron Paul and Newt Gingrich in the race, Republicans and Democrats seem to be marking Tuesday as the official beginning of the 2012 general election, which figures to pit President Obama against Romney.

“Santorum’s out,” a fundraising email from the Democratic Congressional Campaign Committee read late Friday. “That means the 2012 general election is on.”