Harper hit the two home runs in a Monday game against the Miami Marlins. 

Sen. Mark WarnerMark Robert WarnerOvernight Cybersecurity: Equifax hit by earlier hack | What to know about Kaspersky controversy | Officials review EU-US privacy pact Overnight Tech: Equifax hit by earlier undisclosed hack | Facebook takes heat over Russian ads | Alt-right Twitter rival may lose domain Facebook under fire over Russian ads in election MORE (D-Va.) was in the ballpark in Washington during the game.

And Senate Majority Leader Harry ReidHarry ReidThe Memo: Trump pulls off a stone-cold stunner The Memo: Ending DACA a risky move for Trump Manchin pressed from both sides in reelection fight MORE (D-Nev.) tweeted later on in the game that he hoped 2013 would be an "MVP season" for Harper. Harper, who is 20 years old, won the 2012 National League Rookie of the Year award.

Elsewhere on opening day, Sen. Chris MurphyChristopher (Chris) Scott MurphySenate Dem: Graham-Cassidy is an 'intellectual and moral garbage truck fire' Dems call for action against Cassidy-Graham ObamaCare repeal Murphy fires back at Trump on filibuster MORE (D-Conn.) struck what could be a pessimistic note for Red Sox fans.

The Red Sox faced off against the New York Yankees.